Quick Summary

The Schlage L9070 is one of those part numbers that turns up on a schedule with no explanation attached. It is a mortise lock, it is a classroom function, and the difference between it and the function next to it in the catalogue decides how a room actually gets used.

This guide covers what the L9070 does, how classroom differs from storeroom, what the related functions change, which parts are serviceable, and what to confirm before ordering.

What Is the Schlage L9070?

It is the classroom function in the L Series mortise lock range, with lockdown from the exterior only.

In practice that means a key in the outside cylinder locks or unlocks the outside lever, and it stays as it was left. Leave it unlocked and anyone can walk in. Lock it and the outside lever is fixed until a key changes that. Nobody inside the room can change the state of the outside lever.

The inside lever always retracts the latch. That is not a convenience; it is how the door meets the requirement that people can always leave. Our commercial mortise lock guide covers how the L Series is built around that principle.

Why is it called a classroom function?

Because that is the pattern a teaching room needs: unlocked while the room is in use, locked when it is not, changed by whoever holds the key. The name describes the behaviour rather than restricting where it can be fitted, and the same function suits meeting rooms, labs and consulting rooms.

How Is Classroom Different From a Storeroom Function?

A classroom function can be left unlocked. A storeroom function cannot.

On a storeroom lock the outside lever is permanently rigid, and a key retracts the latch for one entry before the door relocks behind the user. There is no state in which the outside lever simply works. That is correct for a plant room and wrong for a classroom, where people come and go all day.

The practical consequence is what happens when somebody props the door. On a classroom function the right answer is to unlock the lever with a key so the door works normally. On a storeroom function there is no such option, which is exactly why doors with storeroom locks end up with wedges under them. Our storeroom lock guide covers that function in detail.

Does the key stay in the lock while it is unlocked?

No. The key changes the state and comes out. That is what makes the function useful: the condition persists without anybody holding anything, and the next change needs the key again.

What Does the L9071 Add?

Lockdown from the inside as well as the outside.

On the L9071, a key cylinder on the inside face lets somebody in the room lock the outside lever without going out into the corridor. The inside lever still works, so egress is unchanged. What changes is who can secure the door and how quickly.

That difference is the reason the function exists. On an L9070 a room can only be secured by somebody standing outside it with a key, which is not always practical. Where the requirement is for occupants to secure themselves, the L9071 is the function that does it.

Does locking from inside affect getting out?

No, and it must not. On both functions the inside lever retracts the latch mechanically whatever the outside lever is doing. Locking down a room secures it against entry, never against exit, which is the line every one of these functions is designed around. Our lock function codes guide covers how the whole set is organised.

What Is Holdback and Why Does the L9076 Have It?

Holdback keeps the latch retracted so the door is push and pull, without anyone propping it.

On a holdback function the latch can be held back deliberately, so the door simply opens and closes without latching at all. That suits a room that is open for a whole session, or a corridor door that needs to be free during busy periods, and it removes the wedge from the equation.

It is not appropriate everywhere. A door that must latch, including any fire rated opening, cannot have its latch held back, which is why holdback is a separate function rather than a feature on every lock. Our fire rating guide covers why positive latching matters.

How do you tell if a door has holdback fitted?

Operate the lock with the door open and see whether the latch can be left retracted. On a standard function the latch springs back every time. On a holdback function it can be set and will stay. Checking takes seconds and settles an argument that otherwise runs on assumption.

Which Parts Are Serviceable on These Locks?

Most of them, which is the main practical advantage of a mortise lock.

The lock case, the trim, the cylinder, the spindle and the strike are all separate items. A worn lever does not need a new lock. A rekey does not touch the case. A damaged faceplate is a faceplate. The one component that carries the function is the case itself, and that is the one to change when the door needs to behave differently.

Is the lock case specific to the function?

Yes, and that is the point. The case contains the mechanism that decides what the key and each lever can do, so cases are listed against the functions they serve. A case listed for one pair of functions is not a universal part, and the listing is the specification rather than a note.

What Goes Wrong on an L9070 Door?

The same things that go wrong on any mortise lock, plus one that is specific to the function.

The general faults are a rounded spindle, a worn hub, a cylinder cam that no longer drives the mechanism, and a latch binding against a misaligned strike. None of these are function related, and our mortise lock repair guide covers how to separate them.

The function specific complaint is a door that is found unlocked when it should not be. On a classroom function that is almost never a hardware fault. Somebody unlocked the lever with a key and did not lock it again, because the function allows exactly that. Treating it as a lock failure wastes a visit.

How do you check whether the fault is the lock or the door?

Open the door and work everything in free air: both levers, the key in both directions, and the latch. Anything that misbehaves with the door open belongs to the lock. Anything that only appears when the door is closed belongs to the strike, the frame or the alignment.

How Do You Choose Between These Functions on a New Door?

Start from who needs to be able to lock the door and when.

If only key holders need to secure the room, and they can do it from the corridor, the L9070 is sufficient. If occupants need to secure themselves without opening the door, the L9071 is the function. If the door spends long periods deliberately unlatched, holdback should be considered, provided the opening is not required to latch.

Decide that before looking at trim, finish or keying, because those are all independent. The function is the one decision that is awkward to change later, since it lives in the case inside the door. Our L Series parts guide covers how the rest of the assembly is specified.

Does the keying strategy affect the choice?

It affects who can actually use the function. A classroom lock is only as useful as the key distribution behind it, and a function that relies on someone being present with a key fails quietly if that person is not. Our key systems guide covers how that side is planned.

What Should You Confirm Before Ordering?

Six things, and the first is the one most often assumed.

The function currently fitted, read from the lock rather than from the schedule. The function required, decided from the questions above. The handing. The backset and door thickness. The trim design and finish. And whether the cylinder is being reused, replaced or rekeyed.

If the door is being changed from one function to another, confirm whether the existing case can be replaced on its own or whether the trim has to change as well. That answer decides whether this is a small job or a full lockset. Our L283 trim parts guide covers the trim side.

What if the schedule and the door disagree?

Believe the door. Schedules are written before installation and rarely updated afterwards, and a room that changed use five years ago will have hardware that reflects the change rather than the drawing. Read the lock, test the behaviour, and order from what is actually there.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A door closer not closing all the way is one of the most common faults on a commercial opening, and one of the most commonly misdiagnosed. The closer is the visible piece of equipment, so the closer gets adjusted, and the door carries on stopping short.

This guide covers how to read where the door stops, what to rule out before touching an adjuster, which valve actually governs the end of the swing, and when the closer really is the problem.

What Does Where the Door Stops Tell You?

Almost everything, if you watch it rather than the closer.

Release the door from about thirty degrees and let it close with nobody touching it. Watch the gap between the leaf and the frame all the way round as it arrives. A door stopping with an even gap is running out of energy. A door stopping with the gap closed at the top and open at the bottom is being held off by something, and that something is usually the leaf itself rather than the closer.

Repeat from ninety degrees and from full open. A door that closes from ninety but not from thirty has a latch speed or friction problem near the frame. A door that fails from every position has a force problem through the whole swing.

Why start from thirty degrees?

Because it is the hardest test. From wide open the door has momentum to carry it through small obstructions. From thirty degrees there is very little stored energy left, so anything absorbing force shows up immediately. A door that latches reliably from thirty degrees will latch from anywhere.

What Should You Rule Out Before Adjusting Anything?

Everything on the opening that absorbs energy, because the closer is the last thing in the chain.

Start with the hinges. Lift the leaf at the latch edge and watch for movement at the hinge side. A dropped door catches the frame somewhere in the last part of the swing, and no closer setting fixes geometry.

Then the seals. Compression seals and sweeps are designed to be squeezed, and when they stiffen with age or cold they absorb a surprising amount of the closing force. Then the floor covering, which can catch a leaf that used to clear it. Then the latch and strike, which is where most of these faults actually live. Our strike alignment guide covers that last one in detail.

How much difference can a seal really make?

Enough to stop a correctly set closer on a light door. The last few inches of the swing are where the closer has the least energy and the seal has the most compression, so the two work against each other at exactly the wrong moment. A door that latches in summer and not in winter is usually telling you this.

Which Valve Governs the End of the Swing?

The latch speed valve, and only the last few inches of travel.

Most surface closers divide the closing cycle into a sweep and a latch region. The sweep valve controls the long middle part. The latch valve controls the final approach, where the latch has to be driven into the strike. If the door is arriving at the frame and stalling there, the latch valve is the control that matters.

Open it slightly to let the door complete the swing faster and with more authority, in small increments, testing from thirty degrees each time. If opening it fully does not get the door latched, stop. The valve is not the problem and continuing will simply produce a door that slams once the real cause is fixed. Our closer adjustment guide covers each valve in turn.

What if the valves do not change anything at all?

That is a diagnosis in itself. Valves meter fluid, so a valve that produces no change is a valve with no fluid behind it. Check for oil at the shaft, at the body joint and on the door face below the unit. Our guide to a closer leaking oil covers what follows if you find it.

Can the Arm Be the Reason the Door Stops Short?

Yes, and it is the cause most often overlooked on a door that has never worked properly.

The arm converts spring force into movement at the leaf, and how much of that force arrives depends on geometry. A parallel arm on the push side delivers less closing force near the frame than a regular arm on the pull side. If a closer was moved, or fitted in a position the door was not designed for, the geometry may simply not deliver enough force at the end of the swing.

The giveaway is a door that has never latched reliably since installation, as opposed to one that used to and stopped. Wear produces gradual change; geometry produces a problem that was there on day one. Our parallel arm guide covers how the mountings compare.

Does the arm need adjusting as well as choosing?

It does. Most arms are set at installation so the forearm sits at the correct angle to the door when closed, and that preload affects how much force reaches the leaf at the end of the swing. An arm that has been refitted without resetting the preload is a common reason a door stopped latching after unrelated work.

Could the Closer Simply Be Too Small?

On a heavy or exposed door, frequently.

Closer size is matched to door width and weight, and a unit that is undersized will behave exactly like this: adequate through the middle of the swing, out of authority at the end. It is especially common where a door was replaced with a heavier leaf and the original closer was reused, or where an exterior door faces wind pressure the original specification did not account for.

An adjustable spring closer may have range left, which is the first thing to check. A fixed size closer does not, and no adjustment will create force the unit cannot produce. Our closer sizing guide covers matching the unit to the opening, and our spring tension guide covers using the range you have.

Is winding the spring up the right answer?

Only within reason, and only after friction has been dealt with. Spring tension is also what somebody feels when they open the door, so solving a latching problem by raising it can take an accessible opening outside acceptable opening force. Our door clearance guide covers those limits.

What Changes on a Pair of Doors?

Sequence, and the fact that one leaf can prevent the other from closing at all.

On a pair with an astragal, the inactive leaf has to close first. If the active leaf arrives early it lands on the astragal and stops, which looks exactly like a closer problem on the active leaf. The actual fault is that the inactive leaf is slow, or that a coordinator is not doing its job.

Test them separately. Hold the active leaf open, let the inactive one close, then release the active one. If each leaf latches properly on its own, the closers are fine and the sequence is the fault.

Does a mullion change this?

It removes the problem, because each leaf closes against the mullion rather than against the other leaf. That is one reason pairs with removable mullions are simpler to maintain. Our mullion guide covers how those openings are arranged.

Why Does This Matter More on a Fire Door?

Because latching is the function, not a convenience.

A fire rated assembly depends on the leaf closing from any position and latching positively under its own closer with nobody helping. A door that stops an inch short looks closed and is not. In a fire that gap is the difference between a barrier and an opening.

It is also the reason the thirty degree test matters on rated openings specifically. A door that only latches when pushed, or when released from wide open, has not met the requirement. Our fire rating guide covers what else depends on the same listing.

What should be recorded after the repair?

That the door was released from thirty, ninety and full open and latched unaided from each, along with what was changed to achieve it. On a rated opening that record is as much a part of the job as the repair.

What Should You Check Before Ordering Parts?

Whether you are buying a closer, an arm, or neither.

Confirm the closer model from the body or cover, the arm type and mounting, the door width, weight and whether it is exterior, the condition of hinges and seals, and whether the valves still respond. That last point separates a worn out unit from a healthy one on a difficult door.

If friction turned out to be the cause, the order is likely seals, hinges or a strike rather than anything from the closer. Fixing the closer in that situation leaves the original problem in place with a new unit attached to it. Our LCN closer parts guide covers how arms, shoes and brackets are listed.

How do you avoid the same callout in six months?

Fix the cause rather than the symptom, and note what you found. A door that stops short because of a stiff seal will do it again next winter if the seal is left in place and the closer is simply wound up to overcome it. Our maintenance checklist covers catching these before they become callouts.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A Schlage emergency unlock tool is the small item that nobody thinks about until a restroom door will not open and somebody inside is not answering. It exists because privacy locks are designed to be overridden, and the override needs something to turn it.

This guide covers what the tool actually does, how the emergency release inside the lock works, why it is not the same as a lever removal tool, what fails, and how to make sure the override is there when it is needed.

What Does a Schlage Emergency Unlock Tool Do?

It operates the emergency release built into a privacy function lock, from the outside of the door.

A privacy function locks the outside lever from the inside, usually with a push button or a turn piece. There is no key cylinder, because the room is not meant to be secured against the building, only against somebody walking in. What there is instead is a small opening in the outside trim with a slot, a hole or a shallow recess behind it, connected to a plunger that releases the lock.

The tool engages that release and turns or pushes it. The lock unlocks, the outside lever works, and the door opens. The design intent is that this takes seconds and needs no key and no permission.

Why is there no key on a privacy lock?

Because a keyed lock creates a different problem. If a restroom needed a key to override, the person with the key would have to be found first, and the lock would then be part of the building key system with everything that implies. The emergency release gives immediate access without making the door part of the security hierarchy. Our lock function codes guide covers where privacy sits among the other functions.

How Is It Different From a Lever Removal Tool?

They do completely different jobs and only look alike.

A lever removal tool, usually a spanner wrench, depresses a hidden catch so the lever and rose can be pulled off the chassis. It is a service tool, and the door is normally open when it is used. An emergency unlock tool operates a release inside the lock to open a door that is locked and that somebody may be behind.

The confusion is understandable. Both are small, both engage a hole in the trim, and both end up in the same pouch. The consequence of mixing them up is that somebody tries to remove the trim from a door they are trying to open, which wastes the one resource an emergency does not have. Our lever removal tool guide covers the service side in full.

Can you open a privacy lock with a screwdriver or a nail?

Sometimes, and it is worth knowing in an emergency, but it is not a method. The release is sized for a specific tool, and anything approximate rounds out the opening or pushes the plunger out of alignment. A lock that has been opened with improvised tools a few times is a lock whose override will eventually fail at the moment it matters.

Which Locks Have an Emergency Release?

Privacy functions, and only privacy functions, because they are the ones designed to be locked by an occupant.

A storeroom function has no release, because the outside lever is permanently locked and a key is the intended access. A classroom function is controlled by key from outside. An office function is locked and unlocked deliberately by a key holder. None of these are the situation an emergency release is for.

Privacy is different: the person inside locks it, nobody outside has a key, and the building still needs a way in. That is the whole reason the release exists, and it is why checking the function is the first step when somebody asks whether a door can be overridden.

Do hospital and patient room locks work the same way?

They follow the same principle with different hardware. A hospital privacy function gives the occupant privacy and staff a way in, and the override is built around the same idea of immediate access without a key. The specific release and the tool that fits it vary with the lock family, so confirm against the lock rather than assuming the tool on the van fits.

Does a Mortise Privacy Lock Work Differently?

The idea is the same, but the hardware sits in an escutcheon rather than a rose, and the release is part of that escutcheon.

On a mortise privacy lock the inside face carries a turn piece, and on some functions a deadbolt as well. The outside face carries the emergency release. Because the escutcheon is a single plate covering the whole preparation, the release position is fixed by the plate design rather than by a small rose.

That has a practical consequence: the escutcheon is a stocked part in its own right. A damaged outside plate, or one where the release opening has been worn out, can be changed without touching the lock case. Our mortise lock parts guide covers how those assemblies break down.

What changes when the privacy lock also has a deadbolt?

The override has more to do. On functions where the inside turn throws a bolt as well as locking the lever, the emergency release has to retract that bolt too. If it does not, the door stays shut after the lever frees up. Check what the inside turn actually operates before assuming the release covers it.

Why Will My Privacy Lock Not Override?

Usually the plunger or the turn button rather than the lock itself.

The release mechanism is a small plunger that has to move freely when the tool pushes or turns it. It sits behind an opening in the trim, which means it collects dust, cleaning product and whatever else gets near a restroom door. A plunger that has stiffened will resist the tool, and a plunger that has seized will not move at all.

The turn button on the inside wears in the same way. Buttons that are pushed thousands of times develop play, and a worn button can set a lock that the release then cannot clear cleanly.

How often should the override be tested?

As part of routine maintenance, on every privacy door, because it is the one function on the opening that nobody exercises in normal use. The occupant uses the button, the public uses the lever, and the release sits untouched for years. Our hardware maintenance checklist covers where it fits alongside everything else on the door.

Where Should the Tool Actually Live?

Somewhere a person on shift can reach in under a minute, which is rarely where it ends up.

An emergency unlock tool in a technician's van is not an override for a building whose staff need access at night. The usual answer is a small number of tools held at reception, in a facilities office or with a duty manager, with people who know what they are and when to use them.

The second half is knowing which doors they fit. A site with several lock families may need more than one tool, and the only way to find that out calmly is to check in advance rather than during an incident.

What should be written down?

Which doors have privacy functions, which tool each one takes, where the tools are kept, and who is expected to use them. That list takes an hour to compile and removes the part of an emergency that is pure confusion. Our hardware troubleshooting guide covers how to work through the door itself once you are inside.

What Should Happen After an Emergency Unlock?

Someone should find out why it was needed, because an override is a symptom rather than an event.

A privacy lock that had to be overridden once because somebody could not work the inside button is a training matter. A lock that has needed overriding three times in a month is telling you something mechanical is wrong, and the next time may be the time the override does not work either.

Check the inside release, the latch and the strike while the door is open and accessible. Most repeat overrides come from a latch that is binding rather than from anybody misusing the lock. Our mortise lock repair guide covers narrowing that down.

Should the override be recorded?

On any door where occupant privacy matters, yes. A short note of when the door was opened and why protects everybody involved, and over time it is also what shows a particular lock is becoming unreliable before it fails completely.

What Do You Need to Know Before Ordering?

The lock series, the function, and whether you are buying the tool or the mechanism it acts on.

The series decides the tool shape and the release design. The function confirms there is a release at all. And the distinction between tool and mechanism matters, because a door that will not override needs a part, not another tool.

Also note the finish if trim is involved, and whether the opening is in a setting where wear is likely to be high. Restroom and changing room doors live hard, and the components that fail there are the small ones. Our ND Series storeroom lock guide covers the neighbouring functions on the same chassis family.

Can the function be changed instead?

On several series, yes, with a function kit. If a door keeps being locked when it should not be, or privacy is not actually the requirement, changing the function solves the problem more completely than repeating overrides. The lock body stays in the door and the trim and keying are unaffected.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Door closer spring tension adjustment is the control people reach for last and should often reach for first. The speed valves decide how the door moves. The spring decides whether it has enough force to finish the job at all.

This guide covers what the spring actually does, how adjustment differs from the valves, when to change it, what limits how far you can go, and how the arm and mounting change the result.

What Does the Spring in a Door Closer Do?

It stores the energy that closes the door, and it resists you while you open it.

Opening the door compresses the spring inside the closer body. That stored energy is what pushes the door shut when you let go. The hydraulic side does not provide any closing force at all; it only controls how quickly the spring is allowed to release what it holds.

That split explains most closer confusion. If a door closes too fast, the fluid is the problem. If a door closes slowly and then stops short of the frame, the spring has run out of authority before the job was finished. Our hydraulic door closer guide covers how the two halves work together.

Is spring tension the same as closer size?

They describe the same thing from different ends. Closer size is the power rating the unit is built to deliver, usually matched to door width and weight. Spring tension adjustment is how far you can move within that unit's range. An adjustable closer covers several sizes; a fixed size closer delivers one. Our closer sizing guide covers how the size is chosen in the first place.

When Should You Change Spring Tension Rather Than a Valve?

When the problem is force, not speed.

Work out which one you have by watching the door close from about thirty degrees with nobody touching it. If it moves at a reasonable speed and then stops just short of latching, or pushes the latch against the strike without seating it, that is a force problem and the spring is the control. If it reaches the frame but arrives too hard or too softly, that is speed and the valves are the control.

What should you rule out before touching the spring?

Friction, every time. A dragging weatherseal, a worn hinge, a carpet catching the leaf or a misaligned strike all absorb closing energy, and winding the spring up to overcome them makes the door harder to open without fixing anything. Our strike plate alignment guide covers the most common of those causes.

How Is Spring Tension Actually Adjusted?

On an adjustable closer, through a dedicated adjustment at the body, separate from the speed valves.

The important part is that it is separate. Speed valves are small needle adjusters, usually behind the cover or on the end of the body, and they meter fluid. The spring adjustment changes preload on the spring itself and needs noticeably more effort to turn. If an adjuster is easy to turn and changes how fast the door moves, you are on a valve.

Work in small increments and test between each one. Spring adjustment moves the behaviour of the whole swing at once, so a large change often overshoots in both directions: the door now latches firmly and is too heavy to open.

How do you know how far you have gone?

Count and write it down before you start. Note the starting position, count turns, and record where you finish. A closer that has been adjusted by several people without records ends up at a setting nobody chose. Our commercial closer adjustment guide covers the valve side with the same discipline.

What Limits How Far You Can Wind the Spring Up?

Opening force requirements, and they are not negotiable on an accessible route.

Accessible openings limit how much force a person should need to open the door. Spring tension is the single biggest contributor to that force, so a closer wound up to force a difficult door shut can take the opening outside what is acceptable. The door now latches and the people who need it most cannot open it.

That is why friction gets fixed first. Reducing what the closer has to fight lets the spring come back down, which keeps opening force within range while still closing the door properly. Our door clearance guide covers the requirements that apply to the opening as a whole.

Does a fire door change the limits?

It changes the priority. A fire door has to close and latch from any position under its own closer, so there is a floor below which the spring cannot go however light the door needs to feel. Where that floor conflicts with opening force, the opening needs a different solution, such as a power operator, rather than a compromise setting.

How Does the Arm Change What the Spring Delivers?

Considerably, because the arm decides how spring force is turned into door movement.

A regular arm pulls on the door from a position that gives it good mechanical advantage. A parallel arm mounted on the push side works at a less favourable angle and delivers less closing force to the leaf for the same spring setting. That is why the same closer, moved from one mounting to another, can go from closing firmly to stopping short.

Track arm and cush arm installations change it again. A cush arm includes a stop function and trades some of the swing for that control. Our parallel arm closer guide covers how those geometries compare.

Should the arm change instead of the spring?

Sometimes that is the better answer. If the door needs more closing force than the current mounting can deliver, moving to a geometry with better mechanical advantage achieves it without raising opening force as much as winding the spring up would. It is a part change rather than a setting, but it solves the cause.

Does Where the Closer Mounts Affect the Setting?

Yes, and a drop plate or bracket often matters more than people expect.

A closer mounted lower on the leaf, or further from the hinge, changes the leverage it works with. Drop plates exist because many frames do not give the closer the position it was designed for, and the plate restores a workable geometry rather than being an optional extra.

If a closer has been fitted in a compromised position, no spring setting will make it behave properly. The adjustment range is being used to compensate for geometry, which leaves nothing in reserve when the door seals stiffen in winter.

What if the door has a transom or narrow top rail?

Then the mounting options narrow and the plate or bracket becomes part of the specification rather than an accessory. Establish what the opening will physically accept before deciding how much closing force is available, because the mounting decides the ceiling. Our closer installation guide covers the mounting decisions in sequence.

What About Hold Open Arms and Spring Tension?

A hold open arm does not change the spring, but it changes how people treat the door.

The arm holds the leaf at a set position until somebody pushes it out of detent. The spring is still doing its normal job once released. The complication is that a door held open every day is a door whose closer is loaded differently, and users who force it out of hold open put a shock load into the arm and the body.

If a hold open door also has a latching problem, resist the temptation to wind the spring up to compensate for the extra distance it travels. The cause is usually the same friction as on any other door. Our door slamming guide covers the reverse case, where force is already too high.

Can you fit a hold open arm to a fire door?

Not as a mechanical hold open. A fire door has to close on alarm, so anything that holds it open has to release automatically when that happens. A plain mechanical detent arm does not, which is why rated openings use a different arrangement entirely.

What Should You Check Before Ordering Parts?

Whether the closer you have is adjustable at all, and what the opening actually needs.

Identify the model from the body or cover. Confirm whether it is an adjustable spring unit or a fixed size. Note the arm type and mounting, the door width and weight, whether the opening is fire rated or on an accessible route, and what the door is doing wrong in plain terms.

If the unit is fixed size and underpowered, no part will change that and a correctly sized closer is the answer. If it is adjustable and already at the top of its range, the same conclusion usually applies. Our LCN closer parts guide covers how arms, shoes and plates are listed.

How do you leave the door for the next person?

Set, tested and recorded. Release the door from thirty degrees, from ninety degrees and from full open, and confirm it latches from each without help. Then write down the final spring position and valve settings somewhere that survives, because the next person to look at this door will otherwise start from scratch.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

An electric strike for a mortise lock looks like the same job as one for a cylindrical lock, and it is not. The latch is longer, the frame preparation is deeper, and the lock may carry a deadbolt that no strike will ever release.

This guide covers what changes when the lock is a mortise lock, how to choose the strike, which measurements decide it, and what goes wrong when the wrong unit is fitted.

What Changes When the Lock Is a Mortise Lock?

The latch does, and everything else follows from it.

A mortise lock sits inside a pocket cut into the edge of the door, and its latch projects from the lock case rather than from a small cylindrical chassis. That latch is typically longer and squarer than a cylindrical latch, so the keeper it drops into has to be deeper and shaped to receive it. A strike that suits a cylindrical lockset will often accept the mortise latch partway and then stop. Our mortise lock repair guide explains what fails and what you can replace.

The second change is the frame. Mortise locks are common on openings with substantial frames, and the cavity behind the strike has to take a backbox deep enough for the mechanism. Our guide to commercial mortise locks covers how those locks are built, and the strike has to answer the geometry they create.

Does the lock function matter as well?

Yes, more than most people expect. A storeroom function presents a latch only. An office or entry function may present a latch and a deadbolt. A classroom security function changes which side the key controls. The strike only ever deals with the latch, so the function tells you whether releasing the latch is actually enough to open that door.

Why Is Latch Throw the First Thing to Measure?

Because it is fixed by the lock and it eliminates most of the catalogue in one step.

Latch throw is how far the latch bolt projects from the face of the lock when it is fully extended. Electric strikes are listed against a throw figure, and that figure is not advisory. A strike built for a 3/4 inch throw presented with a longer latch will either refuse the latch or hold it at an angle where it never seats properly.

Measure it with the door open and the latch fully out, from the face of the lock to the tip of the bolt. Do not measure the keeper you already have, because the existing strike may be the reason you are standing there.

What if the latch has an anti friction tongue?

Many mortise latches carry a small secondary tongue ahead of the main bolt that reduces drag as the door closes. It has to clear the keeper lip cleanly. If the strike lip is set too far out, the tongue catches and the door checks against the frame before the latch arrives, which reads as a sticking door rather than a strike problem.

Which Strike Suits a Mortise Lock on a Standard Frame?

On most commercial openings, a heavy duty strike from a series built for mortise and cylindrical locks without deadbolts.

These units are designed around the latch a mortise lock presents, with a keeper deep enough to take the bolt and a body sized for a frame cavity. Within a series the variants differ by frame material and backbox depth rather than by how they work, so the choice is driven by the opening rather than by preference. Our 6211 electric strike guide works through that variant logic in detail on one unit. Our electric strike vs magnetic lock comparison explains which suits your door.

How do you pick between variants in the same series?

By the frame, in three steps. Establish the frame material, measure the cavity depth available behind the strike, and confirm the faceplate size needed to cover the existing preparation. Those three answers normally leave a single variant standing. Guessing between them is how a strike arrives that is correct in every respect except that it will not go into the hole.

Why Will an Electric Strike Not Release a Deadbolt?

Because a strike releases a keeper, and a deadbolt is not held by one.

An electric strike works by letting its keeper swing out of the way so the latch can leave the frame. A latch is sprung and retracts under load. A deadbolt is driven out by the key or thumbturn and stays where it is put, so there is nothing for the keeper to release. If the bolt is thrown, the door stays shut no matter what the access control system does.

This matters most on office and entry functions, where users throw the deadbolt at night and the access control system appears to have failed the next morning. The system is working perfectly; the door is simply bolted. Where remote release has to work regardless, the answer is usually an electrified lock rather than a strike, and our electrified mortise lock against electric strike comparison covers that decision.

What do you do on a door that has to have a deadbolt?

Separate the two jobs. Let the deadbolt be the manual, after hours security and let the access control release the latch during the working day, with a clear instruction that the bolt stays retracted while the system is in use. Where that discipline cannot be relied on, the lock itself needs to change.

Should the Strike Be Fail Safe or Fail Secure?

Decide it from what the door must do when the power stops, not from what sounds safer.

Fail secure means the keeper stays locked without power, so the door remains secure and a key still works from outside. Fail safe means the keeper releases without power, so the door can be pushed open. Neither affects escape, because on a mortise lock the inside lever retracts the latch mechanically whatever the strike is doing.

Does the mode change the current draw?

Yes, and it is worth knowing before the power supply is sized. A fail secure strike is energised only while it is being released, so it draws nothing in its resting state. A fail safe strike has to be energised continuously to stay locked, which adds a standing load to every door fitted with one. Our complete electric strike guide covers the supply side in more detail.

What Is the Faceplate For and When Does It Change?

It covers the frame preparation and presents the keeper, and it changes whenever the existing cutout does not match the new strike.

Faceplates are listed separately from the strike body for a practical reason: the frame in front of you was prepared for whatever was fitted first. A replacement strike with a different face leaves a gap or overlaps the stop. Ordering the correct faceplate turns a frame modification into a parts change.

Can you reuse the old faceplate?

Only when it is listed for the new strike. Plates look interchangeable and are not, because the keeper opening and the fixing positions are matched to the body behind them. A plate that is close but not correct holds the keeper slightly out of position, and the latch then lands on the edge of the opening instead of inside it.

Why Does My Electric Strike Buzz But Not Release?

Nearly always voltage at the strike or load on the latch, in that order.

A buzz means the coil is energised, so the signal has arrived. What it has not done is move the keeper. The two common reasons are that the voltage reaching the strike has dropped below what the unit needs after the run of cable, or that the door is pressed against the frame hard enough to load the latch into the keeper so it cannot swing clear.

Test both quickly. Measure at the strike terminals while somebody operates the release, not at the panel. Then ease the door against its swing to take the load off the latch and try again. If it releases with the load removed, the fault is alignment or door closing force rather than the strike.

How do you tell a strike fault from an alignment fault?

Operate the strike with the door standing open. If the keeper moves freely with nothing touching it, the unit is working and the problem lives at the opening. If it does not move with no load at all, the fault is in the strike or its supply. That one test separates most callouts before any tools come out, and our hardware troubleshooting guide covers the rest of the opening.

Does a Fire Rated Door Change the Strike Choice?

It narrows it, because the strike becomes part of a listed assembly.

A fire rated opening is tested and listed as a complete set, and the strike is one of its components. The replacement has to be suitable for that use, and the door has to latch positively every time under its own closer. A strike that releases on loss of power is not normally appropriate on a door that has to stay latched in a fire, so fail secure is the usual answer on those openings.

Positive latching is the part that gets missed. A strike that holds the door closed but does not let the latch seat fully has not met the requirement, even though the door looks shut. Our fire rating guide covers what else on the opening is bound by the same listing.

What about an accessible opening?

Accessible routes limit the force needed to open a door, and a strike contributes to that in one specific way. If the keeper is set too far into the frame the latch has to be dragged out of it, which raises opening force. Setting the strike so the latch leaves cleanly is part of meeting the requirement rather than a refinement, and our door clearance guide covers the rest.

What Should You Confirm Before Ordering?

Six things, and five of them come off the door rather than out of a catalogue.

The lock series and function, so you know what the strike has to work with. The latch throw, measured rather than assumed. The frame material and the cavity depth behind the existing strike. Whether a deadbolt is present. The faceplate size needed to cover the current preparation. And the voltage available at the door, measured at the opening.

Record them before you look at part numbers. Every one of those answers removes options, and a strike chosen without them is a strike chosen on hope. For the parts side of the strikes themselves, our electric strike parts guide covers what is stocked separately.

What if the opening already has an electric strike that never worked properly?

Treat it as evidence rather than as a baseline. A strike that has never worked well is often the wrong throw or the wrong depth for the lock in front of it, and copying its part number repeats the mistake. Measure the lock, measure the frame, and let those numbers select the replacement. Our electric strike installation guide covers setting the new unit once it arrives.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A door closer leaking oil is one of the few hardware faults that announces itself before it stops the door working. There is a smear on the paintwork, then a film on the leaf, and then one day the door swings shut on its own momentum.

This guide covers why these units leak, what the oil is actually doing inside, why topping up is not possible, how to tell a leak from a stain, and what gets replaced.

What Is the Oil in a Door Closer Doing?

It is the control. Everything you feel in a well behaved door comes from fluid being pushed through small passages.

Inside the closer body a spring is compressed as the door opens. On the way shut that spring pushes a piston back, and the piston has to move fluid from one side of itself to the other. The route the fluid takes runs through valves, and the size of those openings is what sets how fast each part of the swing happens. Sweep speed, latch speed, backcheck and delayed action are all the same mechanism with different passages.

Take the fluid away and the spring is still there, but nothing is restraining it. The door closes at whatever speed the spring and the door weight produce, which is why a leaking closer eventually becomes a slamming door. Our hydraulic door closer guide covers how the internals are arranged.

Why can you not just top it up?

Because there is nowhere to put it and nothing holding it in. A commercial surface closer is assembled and filled at the factory and sealed. There is no filling plug, and the valves on the outside are adjusters, not access points. Even if fluid could be introduced, the seal that let the original escape would let the new fluid out as well.

Where Does a Door Closer Usually Leak From?

Three places, and each has a different story behind it.

The pinion shaft is the most common. It is the only part of the sealed body that has to rotate, and the seal around it works every cycle. On a high traffic door that is tens of thousands of movements a year, and seals wear.

The second is the body joint or end cap, where two parts of the housing meet. The third is damage: a struck closer, a door forced past its stop, or an arm levered against the body can crack a housing or distort a joint enough to let fluid past.

How do you confirm it is the closer and not something else?

Clean the area thoroughly, dry it, and look again after a day of normal use. Hinges, overhead stops and operators all sit near a closer and can leave their own stains. A genuine closer leak returns to the same spot and spreads downwards from it. A stain that never comes back was historic.

What Does a Leaking Closer Feel Like Before You See It?

The door changes behaviour, usually at one end of the swing first.

Early fluid loss often shows as a door that closes normally for most of its travel and then arrives too quickly in the last few inches, because the latch passage is the smallest and the first to lose its effect. Later the whole swing speeds up. On a door with backcheck, the resistance near full open fades, and the door starts hitting the wall or the stop.

Users describe it as the closer needing adjustment. Turning the valves at that point produces little or no change, which is itself a diagnostic: a closer that no longer responds to its own adjusters has usually lost the fluid those adjusters work on. Our closer adjustment guide covers what those valves should do on a healthy unit.

Could it be adjustment rather than a leak?

It can, and the test takes a minute. Make a small change to the sweep valve, no more than a quarter turn, and watch the door. A working closer responds visibly. A closer with no fluid behind the valve does nothing, or changes briefly and then reverts. If the adjusters have gone dead, stop adjusting and start looking for oil.

Why Is a Leaking Closer Urgent on a Fire Door?

Because the closer is what makes a fire door a fire door in daily use.

A fire rated assembly relies on the leaf closing from any position and latching positively, with nobody helping it. A closer that has lost its control may still close the door, but it does it at a speed nobody designed for, and a door that bounces off the frame does not latch. A closer with no fluid left may not generate enough controlled force to complete the last part of the swing at all.

Either outcome leaves an opening that looks normal and does not perform. Our fire rating guide covers what the rest of the assembly depends on, and on a rated opening a leaking closer is a replacement rather than a deferred item.

Does it matter on a non rated door?

Less urgently, but it still matters. A door closing uncontrolled is a finger injury risk, it damages the frame and the hardware, and it will eventually break the arm or the fixings. The cost of leaving it is rarely just the closer. Our guide to a door that slams covers the other causes worth ruling out.

Can a Leaking Closer Be Topped Up or Resealed?

Not in the field, and this is the question that comes up on nearly every one of these jobs.

The hydraulic circuit inside a closer is sealed at manufacture and is not built to be opened, refilled and closed again on site. There is no fill point, the fluid specification is not something to improvise, and any air left in the circuit changes how the valves behave. A unit that has leaked has also lost the seal that was holding the fluid in, so refilling it simply starts the leak again.

The practical answer is to replace the part that holds the fluid. On a serviceable range that may be the cylinder assembly rather than the whole closer, which keeps the arm, cover and bracket in place. Our LCN closer parts guide covers how those components are listed.

What about sealants or additives sold for leaks?

They do not address the problem. The leak is a failed seal under pressure, not a porous casting, and anything thick enough to block the path is also thick enough to interfere with the valves. On a rated opening it is worse than useless, because the door has to close and latch predictably and an improvised fix makes that unpredictable.

What Gets Replaced and What Can Stay?

The hydraulic body goes. Most of the rest of the opening usually does not.

On ranges where the cylinder assembly is listed as a separate item, that assembly is the repair, because it is the sealed unit containing the fluid. On others the closer is replaced as a complete unit. Either way, arms, shoes, brackets, drop plates, covers and fixings are stocked separately and a sound one can be reused.

Should you replace the arm at the same time?

Only if it needs it. An arm that is straight, with no play at the pivots, has nothing wrong with it and will outlast another closer body. An arm that has been bent, even slightly, loads the new closer unevenly from day one and shortens its life. Our LCN closer parts guide covers how those components are listed.

Why Did This Closer Fail Early?

Usually because something outside the closer made it work harder than it was sized for.

A closer sized too small for the leaf runs at higher internal pressure for every cycle. A door with a dragging seal or a worn hinge makes the closer fight the opening on the way shut. A door that gets pushed past its stop puts a shock load straight into the body through the arm. None of these show up as a closer fault until the closer is the thing that leaks.

If a replacement unit on the same opening fails again within a couple of years, the opening is the problem rather than the hardware. Our closer sizing guide covers matching the unit to the door.

Does an overhead stop help?

On a door that gets thrown open, yes, considerably. The alternative is that the arm and the closer body absorb the over travel, and they were not designed for it. Where a stop cannot be fitted, an arm designed to limit travel does part of the same job, which is covered in our parallel arm closer guide.

How Do You Deal With the Oil That Has Already Escaped?

Clean it properly, and check what it has run onto.

The fluid will have run down the door face and may have reached the floor. On a painted leaf it leaves a mark that will show through a fresh coat if it is not cleaned first. On a floor it is a slip risk, and in a corridor that matters more than the door does.

Check whether it has reached anything it should not have. Fluid on a strike face or on a latch will attract dust and turn into a paste that affects how the door latches, so those surfaces are worth cleaning even if they look fine.

What should you record before ordering a replacement?

The closer model from the body or the cover, the arm type fitted, how the unit is mounted, whether a drop plate or bracket is in use, the door width and weight, whether the opening is fire rated, and anything about the door that made the old unit work hard. Our closer parts diagram helps match what you are looking at to what you need to order.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A roller strike is one of those parts nobody specifies until a door starts misbehaving. The door closes, stops just short, and sits there unlatched until somebody pushes it the last inch.

This guide covers what a roller strike actually changes at the opening, how it differs from the fixed lip strikes most doors are fitted with, when it is the right answer, when it is the wrong one, and what has to be confirmed before ordering a replacement.

What Is a Roller Strike and How Does It Work?

It is a strike whose keeper face is a rotating roller rather than a fixed metal lip.

On a conventional strike, the latch bolt of an exit device slides across a static lip, is pushed back into the device by the ramp of that lip, and then springs out into the keeper once it clears. Every one of those cycles is metal sliding on metal. On a roller strike, that same latch meets a roller mounted on a spindle. The roller turns, the latch rolls over it, and the sliding contact is largely replaced by rolling contact.

The practical result is that less of the door's closing energy is lost at the strike. On a heavy leaf with a strong closer that difference is barely noticeable. On a door where the closing force is already marginal, it is the difference between latching and not latching.

Does a roller strike change how secure the door is?

Not in the way people sometimes assume. The roller changes how the latch gets into the keeper, not how well the keeper holds it once it is there. A latch seated in a roller strike is retained by the body of the strike exactly as it would be in a fixed strike. What a roller strike does not do is add deadlocking or resist manipulation on its own, so a door that needs that still needs the hardware designed to provide it.

When Do You Actually Need a Roller Strike?

When friction at the strike is the reason the door is not latching reliably, and the alignment is already correct.

That second half matters more than the first. A roller strike is a friction fix. If the latch is landing high, low or short of the keeper, friction is not the problem and a roller will not help. Our strike plate guide covers the geometry side, and alignment should be proven before any part is changed.

Could the closer be the real problem?

Frequently. A closer with latch speed set too low cannot drive the latch over any strike, roller or not. A closer with latch speed set too high throws the door at the frame and it rebounds. Before changing the strike, watch the last few inches of the swing and see whether the door is arriving with too little energy or too much. Our guide to a door that slams covers the adjustment side of that behaviour.

Which Roller Strike Suits Your Device?

The device decides it, not the frame.

Exit device strikes are matched to the latch they receive. The latch throw, the latch shape and the height at which it presents all come from the device, so a strike that suits a rim device on one series will not necessarily suit another. Narrow stile openings narrow the choice further, because there is less frame face to work with.

Does device length change the strike?

It can, and this catches people out. Some roller strikes are listed against a specific device length because the latch position and the reinforcement behind it differ on that build. A strike described as suiting a five foot device is not a general purpose part, and fitting it to a shorter device leaves the latch meeting the roller off centre.

What Do You Give Up by Choosing a Roller Strike?

A moving part where there previously was none.

A fixed lip strike is a piece of shaped metal. It wears, but it has nothing to seize, and a worn lip still works after a fashion. A roller strike has a roller on a spindle, and a roller that stops turning is worse than a fixed lip, because it presents a smaller contact face for the latch to drag over. In a dusty environment, or one where the opening is washed down regularly, that is a real consideration.

What is the fixed lip alternative?

A standard panic strike. It is the part most exit devices leave the factory expecting, and on a well aligned opening with a correctly set closer it does the job for years. If the diagnosis points at alignment rather than friction, this is usually what should go back on.

When Should the Strike Also Act as a Door Stop?

When the opening has nowhere sensible to put a separate stop, and the door is over travelling.

An integral stop strike combines the keeper with a stop face, so the leaf is arrested at the frame rather than by a floor or wall mounted stop. On openings where a floor stop would be a trip hazard, or where the wall behind the door is glazed, that combination solves two problems with one part.

It is not a free upgrade. The stop face takes the full impact of the door every time somebody pushes it hard, and that load now goes into the frame at the strike rather than into a stop designed for it. On a door that gets thrown open, a separate stop is still the better engineering answer.

Does a mullion change the strike choice?

Yes, because on a pair of doors with a removable mullion the strike is mounted on the mullion rather than the frame, and the mullion defines where the latch lands. Our mullion guide covers how those openings are put together and why the strike cannot be chosen independently of the mullion.

Does a Roller Strike Affect a Fire Rated Opening?

It is part of the assembly, so yes, it has to be treated as such.

A fire rated door is listed as a complete assembly: leaf, frame, hinges, closer, exit device and strike. Changing the strike changes a component of that assembly. The replacement has to be one that suits the device and the opening as listed, and positive latching has to work every time, because a fire door that does not latch is not performing its function at all.

This is also where the friction argument carries the most weight. A fire door is required to close and latch under its own closer with no help from anybody. If the strike is the reason it needs a push, that is not a comfort issue, it is a performance failure. Our fire rating guide covers what else on the opening is bound by the same listing.

What about an accessible opening?

Accessible routes limit how much force a person should need to open a door. Opening force and latching force are different measurements, but they share a cause: an opening fighting itself. A strike that drags increases the force the closer has to supply, and the usual fix for that is to wind the closer up, which then raises the force a person needs to push the door open. Reducing friction at the strike can let the closer come back down.

What Should You Check When Fitting a Roller Strike?

Four things, in this order: position, engagement, fixings and function.

Position means the strike sits where the latch actually arrives, not where the old one happened to be. Engagement means the latch is seating fully into the keeper rather than catching on the edge of it. Fixings means the screws are landing in frame material or reinforcement rather than air. Function means the door latches from a standstill under the closer alone, several times, with nobody touching it.

How tight should the fixings be?

Firm, not forced. Over tightening into a thin frame face can pull the strike body out of shape, and a distorted body is the quickest way to stop a roller turning. If the screws feel like they are turning without biting, the fixing holes are worn and the frame needs addressing before the strike goes back on.

When Is the Strike Not the Problem at All?

More often than the symptoms suggest.

A door that will not latch is reporting a symptom, not a diagnosis. Hinge wear drops the leaf and moves the latch down. A sagging frame moves the keeper. A dragging weatherseal absorbs closing energy before the latch ever reaches the strike. A device whose latch no longer throws fully presents less bolt to engage with. Each of those produces the same complaint at the door, and each is unaffected by fitting a roller.

The quick discrimination is to open the door, operate the device by hand, and watch the latch. If the latch is sluggish, short or sticky with the door open and nothing touching it, the fault is in the device. Our hardware troubleshooting guide covers how to work through the rest of the opening, and the rim exit device guide covers how the latch end of those devices is put together.

What should you record before ordering?

The device series and configuration from the stamping, the device length, whether the opening is a single or a pair, whether a mullion is involved, whether the door is fire rated, and a note of where the latch is currently landing relative to the cutout. That last one is what tells you whether you are ordering a roller strike to solve a real friction problem or about to fit a new part to an old alignment fault.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A commercial door operator is the unit that opens the door under power and then controls it closed again. When one is reported as broken, the fault is often somewhere else entirely on the opening.

This guide covers how to separate an activation fault from an operator fault, what actually fails on these units, which parts are ordered separately, and what has to be checked before the opening goes back into service.

What Is a Commercial Door Operator and How Is It Different From a Closer?

A closer only controls the door on the way shut. An operator does that and also opens the door under power.

That difference is the whole reason the part count is higher. An operator needs a control board, a power supply, activation inputs and usually a motor or a powered assist, none of which a closer has any equivalent for. It also takes over the closing function, which is why you rarely see an operator and a separate closer on the same leaf.

Low energy operators are the type most commonly found on commercial openings that are not full automatic entrances. They open slowly enough that the door does not need the guard rails and sensors a high energy automatic door requires, and they are activated deliberately, usually by a push plate or a touchless switch.

Does an operator remove the need for a door closer?

Yes, on that leaf. The operator controls the door closed, so there is no second closer fitted. The consequence is that a hydraulic fault inside the operator presents as a door that slams or drifts rather than as a door that will not open. Technicians who expect operator faults to be electrical can spend a long time on the wiring of a unit whose only problem is on the closing side.

How Do You Tell an Activation Fault From an Operator Fault?

Make the signal happen a different way and see whether the door moves.

This is the single most useful test on these units. If the push plate does nothing but a second activation device opens the door, the operator is fine and the plate or its wiring is not. If no activation method moves the door, the fault is in the operator, its supply or the common wiring both devices share.

Why do activation devices fail so often?

Because they are the part people touch. A push plate takes thousands of impacts, often from elbows, trolleys and wheelchair footplates rather than hands. Touchless switches avoid the impact but introduce a sensing range that can drift or be obstructed. Either way, these devices sit in the most abused position on the opening and their wiring runs through the busiest part of it.

Why Does the Door Work Sometimes and Not Others?

Intermittent operation almost always means a connection, not a component.

The hinge side of a powered door is where cabling has to cross from a static frame to a moving leaf, and that crossing flexes every single cycle. Over tens of thousands of cycles a conductor inside a transfer or a cable kit work hardens and breaks, often while the insulation looks perfect from outside. The door then works when the conductor happens to be touching and fails when it is not.

The giveaway is a fault that correlates with door position. If the unit behaves differently with the door open than closed, suspect the crossing before you suspect the board. Our power transfer guide covers how those crossings are built and what they are rated for.

Can you test a flexing conductor without stripping the opening?

Usually yes, by cycling the door slowly while watching for the fault to appear and disappear at a repeatable point in the swing. A conductor that is broken but touching will often restore when the leaf reaches a particular angle. That repeatability is what separates a cable fault from a board fault, because a failing board does not care where the door is.

What Fails Mechanically on a Door Operator?

The arm, the hydraulics and the mountings, in roughly that order of visibility.

The arm is the link between the operator and the door, and it takes every bit of the load in both directions. On a door that gets pushed open faster than the operator drives it, the arm takes impact loading it was never intended to see. Bent arms, worn pivots and loose arm fixings all show up as a door that moves unevenly or makes noise through part of its travel.

Hydraulic faults inside the unit present on the closing side, because that is the part of the cycle the hydraulics control. A door that opens correctly under power and then slams, drifts or stops short has an operator problem even though the powered half of the cycle looks perfect.

Can the arm be replaced on its own?

Yes, and it frequently is. Arms are supplied as separate parts precisely because they are the component most likely to be damaged by misuse while the operator itself is still sound. Replacing an arm is a far smaller job than replacing a unit, and on a door that has been forced open it is often the only thing needed.

What Changes When the Operator Is on a Pair of Doors?

Sequencing, and the fact that one fault can look like two.

On a pair, each leaf normally has its own operator, and the two have to open and close in the right order so the leaves do not collide and any astragal closes correctly. A sequencing fault therefore presents as two doors behaving oddly when only one unit is actually wrong.

Dual egress pairs add another wrinkle, because the leaves swing in opposite directions. The operators are configured for that arrangement rather than being interchangeable with a standard pair, so a replacement has to match how the opening actually swings, not just how many leaves it has.

Which leaf should you work on first?

The one that is wrong on its own. Disconnect or disable the second leaf, prove the first behaves correctly in isolation, then do the same for the other. Trying to diagnose a sequencing problem with both leaves live is how a single bent arm turns into a two unit replacement quote.

What Do You Have to Check Before Putting the Opening Back in Service?

That the door still meets the requirements that apply to it, not just that it opens.

Low energy powered doors are governed by a standard covering how fast they may open, how fast they may close and how much force they may exert. The opening itself is separately governed by the usual accessible door requirements for clear width, manoeuvring clearance and hardware height. A repair that restores motion but leaves the unit opening faster than permitted has not finished the job.

Does the door still have to open by hand?

Yes. On a low energy operator the leaf must remain operable manually, because the opening has to work in a power failure. If the repaired door is noticeably heavier by hand than it was, something in the arm or the operator is binding and the job is not finished. Our door clearance guide covers the accessibility side of what the finished opening has to achieve.

What Should You Check on an Operator Between Callouts?

The things that fail slowly, because those are the ones that turn into emergency visits.

Arm fixings work loose long before an arm bends, and a loose fixing is a two minute job that prevents a part replacement. Activation plates develop play in their mounting before the switch inside them fails. Closing speed creeps as hydraulics age, so a door that latches reliably in January can be stopping short of the strike by July without anybody changing a setting.

Why does closing performance drift over time?

Because hydraulic control depends on fluid behaviour, seals and the condition of the whole opening, and all three change. Add a stiffening weatherseal or a hinge that has started to drag and the same closing force no longer finishes the job. The door has not suddenly broken; the margin it was set up with has been used up.

When Is It Worth Repairing Rather Than Replacing?

Whenever the failure is in a part that is supplied separately, which covers most of them.

Arms, cable kits, activation switches, mounting hardware and the fixings that hold everything on are all component level items. A unit whose arm is bent, whose activation plate is dead or whose cable has broken does not need replacing. A unit whose hydraulics have failed or whose internal control has failed is a different conversation, and on a door that has already needed several interventions the cumulative cost usually settles the argument.

The honest test is whether the next failure is likely to be the same one. One bent arm on a door that gets forced is a repair. The third bent arm on the same door is a sign that the opening needs a stop, a sign or a rethink rather than another arm.

What should you record before ordering parts?

The operator model from the unit itself, whether the opening is a single, a standard pair or a dual egress pair, whether the fault is electrical or mechanical, which activation devices are fitted and where, the arm type, and whether the door is fire rated. Our hardware troubleshooting guide covers working through the rest of the opening, and the request to exit sensor guide covers the sensing devices that often share wiring with an operator.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Von Duprin templates are the quiet part of an exit device order. Nobody asks for them until the device is on site, and by then the holes are often already in the door.

This guide covers what the templates actually govern, how to pick the right one, why function and handing change the pattern, and what to check before drilling anything.

What Is a Von Duprin Template and What Does It Specify?

It is the dimensioned drawing that locates the device on the door and the strike on the frame.

A template is not a general guide to fitting exit hardware. It is a specific set of dimensions for a specific device, giving the mounting height, the positions of every through hole, the cutouts needed for cylinders and trim, and where the strike has to sit so the latch engages it correctly.

Door and frame preparation is permanent. That is the whole reason templates exist: a hole in the wrong place on a steel door stays there for the life of the door.

Is a template the same as installation instructions?

No, and the two are often supplied separately. The instructions cover the sequence of assembly, the adjustments and the checks. The template covers the geometry. You can follow instructions perfectly and still have a device in the wrong place if the template was never used. Our exit device installation guide covers the sequence side of it.

Which Template Do You Need for Your Device?

Four pieces of information select it, and all four come off the opening and the order rather than out of a catalogue.

If the series is not known, that is the first thing to settle rather than the last. Our Von Duprin series guide covers how the ranges are distinguished, and the selection guide covers how a series is chosen in the first place.

Does the device length change the template?

It changes the mounting dimensions along the door, because the device has to be centred on the leaf and the end cap has to land somewhere sensible. A device sized for one door width fitted to a narrower leaf will not place its fixings where the template expects, which is why device length is confirmed against the leaf rather than assumed from the old device.

Why Does the Device Function Change the Template?

Because function adds hardware, and hardware needs holes.

A plain mechanical device needs the baseplate fixings and the latch arrangement. Add cylinder dogging and the door needs a cutout for the cylinder. Add outside trim and the door needs the trim fixings and the spindle or tailpiece hole. Add electrification and the door needs a route for conductors, which usually means a transfer position as well.

Each of those additions is a different drawing, not an annotation on the same one. A device ordered with electric latch retraction and fitted to a door prepped for a mechanical device will be short of at least one hole.

What about conversion kits?

Conversion kits exist precisely because the hole pattern is the expensive part. A kit that converts a device from one dogging type to another, or adds motorised retraction, is designed to work within the preparation that is already there wherever possible. Our conversion kit parts guide covers one of the common examples.

How Does Handing Affect the Hole Pattern?

It mirrors it. Everything that was on the left is now on the right.

Handing describes which edge of the door the hinges are on and which way the leaf swings. On an exit device it determines which end of the rail carries the latch and which carries the end cap, and therefore where every asymmetric feature sits.

The failure mode is unforgiving. A template read for the wrong hand produces a door with the latch cutout at the hinge end. There is no adjustment that recovers from that.

How do you establish handing before ordering?

Stand on the outside of the door, the side you would need a key for. If the hinges are on your right and the door opens away from you, it is one hand. If they are on your left, it is the other. Write it down at the opening rather than reconstructing it later from memory.

On a pair of doors, hand each leaf separately. The two are not the same, and one of the most common ordering errors on pairs is applying one hand to both. Our mullion guide covers the related decisions on pairs.

What Does the Template Say About Reinforcement?

Where the fixings need something solid to land in.

Exit devices concentrate load at the center case and at the latch end. On a hollow metal door, that load needs internal reinforcement at the right positions, and the template is where those positions are defined. On a timber door, the equivalent question is whether the fixings are reaching solid material or just the skin.

This is the part of the drawing that gets skipped most often, because the consequence is delayed. A device fixed into unreinforced skin works perfectly on the day and loosens over the following months.

Does the frame need preparation too?

Yes, and it is easy to forget when the attention is on the door. The strike position is part of the template, the frame may need reinforcement behind it, and on a mullion arrangement the mullion fixings at head and sill are part of the same drawing.

Can You Fit a New Device to an Existing Door Prep?

Often, and that is what retrofit kits are for. The question is whether the existing holes match what the new device needs.

Retrofit works when the replacement device shares enough of the original pattern that the existing holes can be reused, with any extras drilled and any surplus covered. It stops working when the two patterns differ in the centreline height or in the latch position, because those cannot be hidden.

How do you record an existing prep?

Measure from fixed references and photograph with a tape in shot. Record the centreline height from the floor, the distance of each hole from the latch edge and from the floor, the diameter of each hole, and the cutouts for any cylinder or trim.

That record is what lets a supplier tell you whether a given device will land on the holes that exist. A description of the old device is not enough, because two devices from the same series can have been prepped differently depending on their function.

What Goes Wrong When the Template Is Ignored?

The pattern across all five is that the cheap errors reveal themselves immediately and the expensive ones do not. Reinforcement and strike position are the two that will be somebody else's call out.

Does a fire rated opening change anything?

It raises the stakes considerably. A rated assembly is tested as a set, and site drilling beyond what the hardware listing allows can take the opening outside what was certified. Templates matter more here, not less. Our fire rating guide covers what is permitted on a rated assembly.

How Do Templates Differ Between Door Types?

Mostly in what the fixings land in and what the latch end has to reach.

A hollow metal door needs reinforcement positions defined. A timber door needs fixings that reach solid material rather than veneer. An aluminium stile door is dimensionally constrained by the stile width, which limits what will fit at all. A glass door with a rail at top and bottom limits the mounting position to the rail.

Those constraints are why the door material is one of the four inputs that selects the template rather than a detail.

What changes on a concealed vertical rod device?

Everything inside the door. A concealed rod device routes rods through the leaf to latch at the head and the sill, so the preparation is internal rather than only through the face. That makes retrofitting one far more involved than retrofitting a rim device, and it makes the template non negotiable. Our concealed vertical rod guide covers the configuration in detail.

What Should You Check Before Drilling?

Five things, in this order, and all of them before the drill is picked up.

That the template matches the exact device on the bench, including its function. That the hand is right, confirmed at the door rather than from the paperwork. That the centreline height clears the closer arm, any glazing and any existing trim. That the fixings have something to land in. And that the strike position on the frame has been marked as part of the same exercise rather than left until the device is on.

What if the device has not arrived yet?

Then do not drill. The number of openings prepped from a template for the device that was ordered and then fitted with the device that was delivered is not small. Confirm the device in front of you against the drawing in your hand, every time.

For a worked example of how a template governs a different category of hardware, our door closer installation template guide covers the same principles applied to closers, and the 98 and 99 Series parts guide covers the components that the pattern has to accommodate.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Electric strike or magnetic lock is one of the first questions on any access control job, and it is often answered by habit rather than by the opening. Both put a door under the control of a reader or a panel. They go about it in completely different ways, and those ways suit different doors.

This guide compares the two on the points that actually decide the choice, and sets out which opening suits which.

What Is the Basic Difference Between an Electric Strike and a Magnetic Lock?

An electric strike does not lock anything. It releases something that is already locked.

The door has a lock on it with a latch. The strike sits in the frame where that latch lands. Normally it holds the latch. When it is signalled, it lets go, and the door can be pushed open even though the lock is still locked.

A magnetic lock is the opposite. There is no latch involved at all. An electromagnet on the frame and a steel armature on the door hold the two together by magnetic force, and the door is held shut by nothing else.

Why does that distinction matter so much?

Because it decides what happens when something goes wrong. A strike that loses power can still leave a locked door, because the mechanical lock is doing the work. A maglock that loses power has nothing left. Every other difference between the two is downstream of that.

Which One Keeps the Door Locked in a Power Cut?

The electric strike, provided it is specified fail secure.

A fail secure strike holds the latch when power is removed, so the door stays locked from outside exactly as the mechanical lock intended. A fail safe strike releases, by design, for openings that have to open in an emergency.

A magnetic lock has no fail secure option. Remove the power and it lets go, because the power is the lock. That is not a limitation to be worked around, it is how the product works, and on many openings it is the reason the maglock was chosen.

Does that make a maglock less secure?

Not in normal operation. It makes it unsuitable for openings that must stay secure through an outage, which is a different statement. A store room, a plant room or an equipment cage is strike territory precisely because the requirement is to stay locked no matter what.

Which Is Easier to Install?

It depends entirely on the frame.

An electric strike needs a cutout in the frame deep enough for its backbox, plus a cable route to that point. On a new frame or a frame that already has a strike prep of the right size, that is straightforward. On a narrow aluminium stile or a frame with no room behind it, it can be impossible.

A magnetic lock needs no cutout at all. It bolts to the surface of the frame and the door, which is why it is the standard answer on glass doors, on frameless arrangements and on openings where cutting the frame is not an option.

What does each one do to the door?

The strike does nothing to the door. The door keeps its lock, its latch and its preparation, and the only change is in the frame. That is a genuine advantage on a door that is difficult or expensive to modify.

The maglock puts an armature on the leaf, through bolted, and that means fixings through the door at a defined height. Our maglock installation guide covers the mounting in detail, and the electric strike installation guide covers the other side.

How Do the Two Compare on Egress?

This is the comparison that decides more openings than any other, and it is the one most often left until last.

With an electric strike, egress is already solved. The lock on the door still works mechanically from the inside, so somebody leaving turns the lever and goes, whatever the strike or the access control system is doing. Nothing has to be added.

With a magnetic lock, there is no mechanical path at all. The door is held by magnetism, and the only way to open it is to take the power away. Codes treat electrically locked egress doors as a special case, with conditions that typically include a manual release device on the egress side, release on loss of power and release on fire alarm activation. What is required on a given opening is decided by the authority having jurisdiction.

So a maglock always needs more hardware?

In practical terms, yes. A maglock opening is a designed arrangement rather than a single product: the lock, the release device, the sensing and the interfaces to the alarm system. Our request to exit sensor guide covers one of the components that usually appears, and the delayed egress guide covers the case where the door has to hold briefly before releasing.

Which Draws More Power?

The magnetic lock, by a wide margin, and continuously.

A fail secure electric strike sits idle. It draws current only while it is being released, which on a normal door is a few seconds a day in total. A magnetic lock is energised every moment the door is secured, which on most doors is almost all the time.

That matters for two reasons. The supply has to carry the total continuous load of every maglock on the system, and the battery backup has to carry it for the required standby period. A building with twenty maglocks has a very different power design from a building with twenty fail secure strikes.

What about a fail safe strike?

A fail safe strike is also held by power, so its draw profile is closer to a maglock than to a fail secure strike. If the comparison is specifically fail safe strike against maglock, the power argument largely disappears and the decision moves back to the frame and the egress arrangement.

Which Is More Secure?

They fail in different directions, which makes a single answer misleading.

An electric strike relies on the latch and on the frame around it. Its weak points are mechanical: a worn keeper, a latch that is not fully engaging, a frame that has been attacked around the strike cutout.

A magnetic lock relies on surface contact and on continuous power. Its weak points are an armature that is not meeting the magnet flat, faces that have corroded or been painted, and anything that interrupts the supply.

In practice the deciding factor is maintenance rather than design. A well aligned maglock outperforms a neglected strike, and a well maintained strike outperforms a maglock holding on half its face.

Does monitoring change the picture?

Considerably, and it applies to both. A door position switch tells the system whether the door actually closed rather than only whether it energised the lock. On a maglock that is close to essential, and on a strike it is still worth having. Our door position switch guide covers how the signals fit together.

What Does Each One Need in Maintenance?

Different things, on different intervals.

An electric strike wears mechanically. Springs lose tension, keepers develop a groove where the latch sits, and faceplates get bent by levering. Those parts are stocked individually, so service is a component swap rather than a replacement. Our electric strike parts guide lists what is available.

A magnetic lock has no moving parts, which sounds like no maintenance and is not. What it needs is clean, flat contact between two faces, and that degrades quietly. Paint, corrosion, grit and a drifting alignment all reduce holding force without producing any symptom until somebody pulls on the door.

Which one tells you when it is failing?

The strike, usually. A worn strike gets noisy, sticky or slow, and somebody reports it. A maglock holding at half strength behaves identically to one holding at full strength until the day it does not hold at all. That silent degradation is the strongest argument for scheduled checks on maglock openings.

Which One Suits Your Door?

Work through the opening in order and the answer usually appears before the end.

Can you use both on the same opening?

It happens, usually on high security doors where a maglock supplements a mechanical lock and electric strike. It doubles the power load and doubles the egress complexity, so it needs to be a deliberate decision rather than a belt and braces reflex.

Where the opening is fire rated, both options narrow. A rated assembly is tested as a set, and what can be added to it is constrained. Our fire rating guide covers that, and for the full detail on each technology see our complete electric strikes guide and electromagnetic lock parts guide.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

The word rim causes more confusion in commercial door hardware than almost any other term, because it describes a mounting method rather than a product. Ask ten people what a rim lock is and you will get answers ranging from a Victorian box lock to a modern exit device.

Both are correct, and that is the problem. This guide sets out what rim actually means, where it turns up on commercial doors, and what you need to know when ordering parts for it.

What Is a Rim Lock?

A rim lock is a lock whose body is mounted on the surface of the door rather than buried inside it.

Everything else follows from that. The door needs through holes rather than a routed pocket. The lock can be seen and reached without taking anything apart. Servicing happens with the door hanging, not with the lock case pulled out of the edge. And the lock sits proud of the face, which is why rim hardware is specified where appearance matters less than access.

Is a rim lock an old fashioned thing?

The historic surface mounted box lock is where the name comes from, and it still appears on period buildings. In current commercial specification, though, rim describes a mounting method used on thoroughly modern hardware, most visibly on exit devices.

So a rim device on a fire exit in a new building and a rim lock on a church door from 1880 share a principle and nothing else.

How Is a Rim Lock Different From a Mortise Lock?

A mortise lock lives inside a rectangular pocket cut into the edge of the door. A rim lock lives on the surface. That changes the preparation, the servicing, the security profile and the parts list.

Neither format is better in the abstract. A mortise lock buys concealment and a heavier mechanism inside the door. A rim device buys access, simpler preparation and faster servicing. Our comparison of mortise and cylindrical locks covers the third format in the same terms.

Can a rim device replace a mortise lock on the same door?

Sometimes, but it is a door preparation question rather than a hardware question. The mortise pocket does not disappear when the mortise lock comes out, and a rim device fixes through the face in a completely different pattern. Expect a filler plate and new fixing positions rather than a straight swap.

Where Do You Find Rim Hardware on a Commercial Door?

Overwhelmingly on exit doors, as rim exit devices.

A rim exit device latches into a strike mounted on the frame, which makes it the simplest of the four exit device configurations. There are no rods running to the head and sill, no lock case in the door edge, and nothing concealed inside the door. For a single door with a frame to latch into, it is the default choice.

The second place the word turns up is on the cylinder. A rim cylinder is the format used to key a rim device from the secure side. Our rim exit device guide covers the devices themselves in detail.

When is a rim device not the right choice?

On a pair of doors with no mullion, where there is nothing in the middle for a rim latch to engage. On a door that has to latch top and bottom for fire performance. And where the aesthetic specification rules out surface mounted hardware. In each of those, a vertical rod or mortise configuration takes over, as our concealed vertical rod guide covers.

What Is a Rim Cylinder and How Does It Attach?

A rim cylinder is a cylinder designed to be held against the outside face of the door by a backplate fitted on the inside, rather than threaded into a lock body.

The sequence is the clue to how it works. The cylinder goes through the door from outside. The backplate goes on behind it. Screws through the backplate pull the cylinder tight against the face. A tailpiece or cam on the back of the cylinder then reaches into the device and operates it.

Why does the backplate matter so much?

Because it is the only thing holding the cylinder in the door. A mortise cylinder is held by its own thread in the lock. A rim cylinder is held by a plate and two screws, and if those loosen the cylinder can turn or move in the hole.

A cylinder that spins when a key is turned is a backplate problem far more often than a cylinder problem, and the backplate is a stocked item in its own right.

What Does the Cam or Tailpiece Do?

It is the link between the cylinder and the mechanism. Turning the key turns the plug, the plug turns the cam, and the cam moves whatever the device needs moved.

Cams are not universal. The shape, length and orientation have to suit the device the cylinder is driving, which is why cams are listed as separate parts rather than assumed. Fitting a cylinder with the wrong cam gives you a key that turns smoothly and achieves nothing.

Does the keyway have to match the rest of the site?

If the building runs a key system, yes, and that is a decision made at order time rather than afterwards. A rim cylinder can be supplied to the site keyway so that existing keys work, which is usually preferable to adding another key to a bunch. Our key systems guide covers how that is organised.

What Strike Does a Rim Lock Need?

One positioned for a surface mounted latch, which is not the same as a strike for a mortise or cylindrical lock.

A rim latch approaches the frame from the face of the door rather than from inside its edge, so the strike has to present its opening in a different plane and at a different depth. Rim strikes are listed as their own family for exactly that reason.

On a pair of doors the picture changes again. The inactive leaf has to present something for the active leaf to latch into, which is where double door strikes and mullions come in.

Can the strike be electrified?

Yes, and it is one of the most common ways to add access control to a rim device. The electric strike replaces the fixed strike in the frame, the device stays as it is, and the opening gains remote release without touching the door. Our electric strikes guide covers the selection, and our strike plate guide covers the mechanical version.

Is a Rim Lock Secure Enough for a Commercial Door?

On the right door, yes, and it is used on millions of them.

The honest answer has conditions attached. Surface mounted hardware is visible and reachable, so the fixings matter. Through bolting rather than wood screws, a sound backplate behind the cylinder, and a strike that is properly anchored in the frame are what make the difference between a rim device that resists attack and one that does not.

The other factor is that a rim exit device on an exit door is usually on the secure side of the opening with no trim outside at all. There is very little to attack, because there is nothing out there to grip.

What about the cylinder as a weak point?

It is the component most exposed on the outside face, and that is worth designing around. Cylinder guards, recessed trim and the backplate arrangement behind the door all exist to make the cylinder harder to attack. On an opening with a history of attempts, those are the parts to look at rather than the device.

What Fails on Rim Hardware?

None of those is a device replacement. The point of rim hardware is that the parts are reachable, so the repair is usually a component swap with the door still hanging. Our panic bar parts guide lists the components for the exit devices most of this applies to.

What should you confirm before ordering rim parts?

Five things. The device series, from the stamping. Whether the part is for the device or the cylinder, because they are separate orders. The cam type where a cylinder is involved. The keyway, if the site runs a key system. And the finish, because rim hardware is visible.

If the cylinder format itself is the open question, our mortise cylinder and rim cylinder comparison is the quickest way to settle it, and the exit device terminology guide covers the naming.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Maglock installation looks like the simplest job in electrified hardware. There is no latch, no strike cutout, no mortise pocket, and the two halves simply have to meet. That is exactly why it gets rushed, and why so many of them end up holding at a fraction of their rating.

This guide covers the mechanical mounting, the power side, the egress arrangements that have to accompany it, and the faults that follow from getting any of the three wrong.

What Does a Maglock Installation Involve?

Three separate pieces of work that have to be planned together.

The mechanical part is mounting the magnet to the frame and the armature to the door so that the two meet flat and square. The electrical part is delivering the correct voltage to the magnet continuously, because a maglock is only locked while it is energised. The third part is everything that lets people out, because a lock that holds by power needs a defined way of letting go.

Treating any of the three as a follow up job is where maglock installations go wrong. The egress arrangement in particular dictates what else goes on the door, and that is easier to design in than to retrofit.

Is a maglock different from an electric strike in installation terms?

Completely. An electric strike goes into the frame and leaves the door untouched. A maglock puts hardware on both the door and the frame, carries its load across the joint between them, and needs power running the whole time the door is locked. Our electric strikes guide covers the alternative where the door preparation is the deciding factor.

Where Does the Magnet Go and Where Does the Armature Go?

The magnet mounts on the frame, usually at the head on the stop side, and the armature mounts on the door so that it arrives against the magnet face when the door closes.

The reason that way round is practical. The magnet is the half that needs wiring, and the frame is the half that does not move. Putting the powered half on a swinging leaf means running conductors across the hinge line for no reason.

How accurately do the two faces need to meet?

Flat and fully in contact. A magnetic lock holds by surface contact, and anything that keeps the two faces apart reduces the hold disproportionately. A small gap, a layer of paint, a build up of dirt or a slight twist in the armature all take holding force away.

This is the single biggest difference between a maglock that performs to its rating and one that can be pulled open by hand. The parts are not usually at fault. The alignment is.

How Is the Armature Fixed to the Door?

Through the door, with the fixings sized for the door thickness, and with the armature left able to move slightly.

That last point surprises people. The armature is not meant to be rigid. It needs a small amount of float so it can settle flat against the magnet face even when the door does not present it perfectly square. Clamping it solid removes that ability and guarantees partial contact.

What holds the magnet to the frame?

A mounting pack sized for the installation, and on many openings a bracket. Not every frame presents a flat surface in the right place, and inward opening doors, glass doors and frameless arrangements all need brackets to put the magnet where it needs to be.

Mounting hardware is supplied as a kit for the same reason screw packs are supplied for locks. The fixings are part of the specification, not consumables from the van.

What Power Does a Maglock Need?

Continuous power, at the voltage the unit is listed for, delivered at the lock rather than at the panel.

Because a maglock is energised the whole time it is locked, its supply sizing is different from a fail secure electric strike that draws nothing until released. Every maglock on a system contributes continuously to the load, which matters most when the building is running on battery backup.

Does the installation need a power transfer?

Only if something on the moving leaf needs power. The magnet is on the frame, so a plain maglock does not. The moment an electrified lock, an exit device with latch retraction or a door mounted sensor joins the opening, conductors have to cross the hinge line, and that is a transfer job. Our power transfer guide covers the options.

What Else Has to Be on the Door Before a Maglock Is Used?

This is the part of a maglock installation that is not optional and not a hardware preference.

Codes treat electrically locked egress doors as a special case, because the lock has no mechanical release. The conditions typically attached include a manual release device on the egress side, release of the lock on loss of power, and release on activation of the fire alarm system. What is required on a specific opening is decided by the authority having jurisdiction.

The practical consequence for the installer is that a maglock is never a single product on a door. It arrives with a release arrangement, and the arrangement is as much part of the installation as the magnet.

Does a motion sensor count as the release?

Sometimes, within conditions, and never as the only element. A request to exit sensor above the door can form part of a designed release arrangement, but what is permitted varies and the sensor is one component of a solution rather than the solution itself. Our request to exit sensor guide covers how those units behave and where they are mounted.

Where a door needs to hold briefly before releasing, that is delayed egress, which is a separate function with its own conditions. Our delayed egress guide covers it.

How Do You Monitor a Maglock Once It Is Fitted?

With a door position switch, and ideally with bond monitoring from the lock itself where the unit offers it.

The distinction matters. The access control system knows it energised the magnet. It does not know whether the door actually closed, whether the armature made contact, or whether somebody has propped the leaf. A door position switch answers the first of those, and it is the component most often left out of a maglock installation. Our Wiegand 26 bit guide explains the format, wiring, limits and OSDP.

Flush or surface mounted switch?

Flush where the door and frame can be drilled and the opening is interior and protected. Surface mounted where drilling is not practical, where the opening is exterior, or where a heavier duty unit is wanted on a door that takes abuse.

Our door position switch guide covers how the switch and the request to exit signal work together on a monitored opening.

Why Does My Maglock Not Hold Properly?

Nine times out of ten the answer is contact rather than current.

Working through that table in order resolves most complaints without replacing anything. A maglock is a simple device, and simple devices fail for mechanical reasons.

Can a maglock be mounted on a door with a closer?

It usually has to be, because the door needs to arrive at the magnet reliably. What matters is that the closer brings the leaf fully home. A door that stops a few millimetres short will energise the magnet with no contact at all, which looks like a lock failure and is a closer adjustment. Our door clearance guide covers the related measurements around the opening.

What Changes on an Exterior Opening?

Water, temperature and corrosion, all of which attack the contact surfaces that the lock depends on.

Weatherized units exist for exactly this reason. On an exterior door the magnet and armature faces are exposed to rain driven across them and to condensation forming on cold metal, and ordinary steel surfaces will discolour and eventually pit. That pitting reduces contact area, which reduces holding force.

Does an exterior maglock need different maintenance?

Yes, and it is simple. The faces want checking and cleaning periodically rather than after a complaint. A maglock on an exterior door that has not been looked at in three years is usually holding at well below its rating, and nobody will know until somebody pulls on it.

What Should You Confirm Before Ordering a Maglock?

Six things, and the first three come off the opening rather than the specification.

Whether the door is interior or exterior, because that decides weatherized or standard. The door thickness, because the through fixings are sized for it. Whether the door swings in or out, because that decides whether brackets are needed. The voltage available at the opening. Whether monitoring is required, and of what kind. And what the egress arrangement will be, because that is the part that has to be designed rather than ordered.

What if the opening already has an exit device?

Then the maglock may not be the right answer at all. A door that already latches mechanically and releases from the inside has most of what a maglock is being asked to provide, and adding one can complicate the egress picture rather than simplify it. For the full component breakdown of magnetic locks themselves, our electromagnetic lock parts guide covers what is supplied separately, and our fire rating guide covers what changes on a rated opening.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Mortise locks are built to be serviced. The case comes out of the door, the trim comes off the faces, the cylinder unscrews and the strike unscrews from the frame. Every one of those is a separate part, which is why a mortise lock repair is usually a component job rather than a replacement job.

What makes these calls go wrong is diagnosing from the symptom instead of from the door. This guide covers how to find the actual fault, what can be repaired, what cannot, and what to confirm before ordering.

What Usually Fails Inside a Mortise Lock?

Less than people expect. The case is a steel box full of levers and springs, and on a normal opening it will outlast several sets of trim.

What fails first is whatever is softest and most used. The spindle, because it transmits every turn of the lever. The hub, because the spindle wears into it. Springs, because they cycle constantly. And the latch bolt face, because it rubs against the strike every time the door closes.

Does a mortise lock wear out from the outside in?

Usually, yes. Damage arrives through the trim, the lever and the key, and works inwards. That is why the parts closest to the user fail first and the parts deepest in the case last the longest, and why a lock that feels rough at the lever is more often a trim job than a case job.

How Do You Tell a Lock Fault From a Door Fault?

Open the door and work the lock in free air.

With the door open, operate the lever, throw and retract the deadbolt, and turn the key through its full travel. Everything the lock does with the door open is the lock. Anything that only goes wrong when the door is closed belongs to the frame, the strike or the door itself.

That single test resolves a large share of mortise lock calls before any tools come out, and it stops perfectly good locks being replaced because a door had dropped a few millimetres on its hinges.

What if the fault is intermittent?

Intermittent faults on an otherwise sound lock are usually environmental. A timber door that swells in humid weather, a frame that moves with temperature, or an exterior opening where debris is finding its way into the case. Note when it happens rather than only what happens, because the pattern is the diagnosis.

Can a Mortise Lock Be Repaired, or Does It Need Replacing?

Both are routine. The question is which part has failed and how much of the rest has aged alongside it.

Repair is the right route when a specific component has failed on a lock that is otherwise sound: a spindle, a spring, a trim plate, a cylinder, a strike. Replacement of the case makes sense when the mechanism itself is worn, when several parts have already been changed, or when the function needs to change.

When does the function decide the answer?

Whenever the room has changed use. A store that becomes an office, or a classroom that needs a different locking behaviour, is a function change rather than a repair. The lock case carries the function, so that is a case order, and the trim and cylinder may well carry over.

Our lock function codes guide covers how the function is expressed in the model number, which matters because two visually identical locks can behave completely differently.

How Do You Get the Lock Case Out Without Damaging the Door?

In order, and with the door supported.

Take the trim off both faces first, then the cylinder, then the faceplate screws at the door edge. The case then withdraws from the mortise pocket. Forcing a case out before the cylinder is clear is how cams get bent and how pocket edges get torn.

On a heavy door, wedge the leaf before you start. A door that swings while you have the case half out will take the weight of the case on the pocket edge.

What should you check while the case is out?

Four things, because the pocket is only open once. The condition of the mortise pocket itself, the state of the wiring if the lock is electrified, whether the faceplate is flat and undamaged, and whether the cylinder threads are clean. Finding any of those later means taking the lock out again.

If the trim is also being changed, our trim parts guide covers what is supplied separately on the face of the door.

What Does a Worn Spindle or Hub Do to the Lock?

It produces the most recognisable fault on any mortise lock: the lever turns, and nothing happens.

The spindle is the shaped bar that carries the turn from the lever through the door into the lock hub. It is the part under the most direct load, and it rounds off at the corners over time. Once it has rounded enough, it spins inside the hub instead of driving it.

A lever that turns a few degrees and then goes slack, or one that works intermittently depending on how hard you turn, is almost always a spindle. Replacing the lock case for that symptom is a common and expensive mistake.

How do you check a spindle without stripping the door?

Take one lever off and look at the spindle end. Sharp, square corners mean the spindle is sound. Rounded or twisted corners mean it has been slipping, and the hub it drives needs looking at as well, because a worn spindle wears the hub it turns in.

Replacing a rounded spindle and leaving a worn hub gives you a repair that fails again quickly. If both are worn, the case goes on the order with the spindle.

Why Does the Deadbolt Throw but Not Retract?

Nearly always because it is under load from the strike rather than because the lock has failed.

When a door has dropped, or the frame has moved, the deadbolt enters its cutout at an angle and jams against the edge. The key then has to overcome that binding as well as turning the mechanism, and at some point it will not.

The test is simple. Open the door, throw the deadbolt and retract it. If it moves freely in free air, the lock is fine and the frame needs attention. Our mortise lock strike guide covers how the strike is dimensioned for the bolt it receives.

Can you force a jammed deadbolt?

You can, and it is how bolts get bent and keys snap in cylinders. Lift or push the door slightly to take the load off the bolt first, then turn the key. If it releases, you have both diagnosed and temporarily solved the problem in one movement.

What Parts Are Stocked Separately for Mortise Lock Repair?

Enough that a complete lockset is rarely the answer.

Screw packs matter more than they look. Refitting a serviced lock with mixed fixings from the van is how the next technician finds a lock that has worked loose in its pocket.

Is the cylinder part of the lock?

No, and that is useful. The cylinder is a separate item with its own cam, which means rekeying an opening never touches the lock case. Our mortise cylinder and rim cylinder comparison covers how the two differ and why the cam matters.

What Should You Confirm Before Ordering Repair Parts?

Six things, and they come off the door rather than out of a catalogue.

The lock series, from the stamping on the case or faceplate. The function, because it decides the case. Which component has actually failed, established by the door open test. The handing, where the part is handed. The finish, because visible parts have to match the rest of the opening. And whether the lock is electrified, because that changes both the case and the wiring arrangement.

What if the lock is unmarked?

Measure and photograph. The backset, the case dimensions, the faceplate size and the arrangement of the latch and bolt together narrow the family quickly. A photograph of the case out of the door, with a tape measure across the faceplate, is usually enough to confirm the part.

For a wider view of the range, our mortise lock parts guide lists components by function, and the commercial mortise locks guide covers how these locks are specified in the first place. If you are still establishing which family of lock is on the door, start with mortise locks versus cylindrical locks.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Panic bar parts diagrams look intimidating because they show fifty numbered items on one page. In practice the device only has five groups, and once you can place a part into its group the diagram stops being a wall of numbers.

This guide walks through those groups in the order a diagram is normally laid out, explains what each one does, and covers how the picture changes between device types.

What Are the Main Parts of a Panic Bar?

A touchpad or crossbar, a center case, a rail with a baseplate, an end cap, and a latch assembly. Everything else on the diagram is a fixing, a spring, a cover or a bracket serving one of those five.

The sequence matters because that is how the force travels. A user pushes the touchpad, the touchpad drives the mechanism in the center case, the center case pulls the latch, and the latch leaves the strike. The rail and end cap hold the whole assembly on the door while that happens.

What does the rail and baseplate group do?

The baseplate is the plate that fixes to the door face, and the rail is the cover that runs along it. Between them they carry the device, set how far it stands off the door, and give the touchpad something to react against.

It is the group people ignore on a diagram, and the group that quietly causes the most puzzling faults. Baseplate screws that have worked loose let the whole device move a fraction every time the bar is pushed, which shows up as a latch that retracts fully one day and not the next. Checking that the baseplate is tight against the door is a thirty second job that saves a long diagnosis.

Is a panic bar the same as an exit device?

Panic bar is the common name, exit device is the term used in product literature, and in everyday use they refer to the same hardware. There is a meaningful distinction in how devices are labelled and listed for different applications, which our exit device and panic bar comparison covers in detail.

What Does the Center Case Do?

It is the gearbox. The center case takes the movement of the touchpad and converts it into the pull that retracts the latch, and on most devices it also houses the dogging mechanism.

Because the mechanism lives there, the center case is the part that determines what the device can do. Dogging, cylinder dogging, alarm modules and electrified retraction all attach to or sit inside this group. That is why two devices with identical rails can behave completely differently.

Why is the center case reinforced?

Because it carries the concentrated load. A rail spreads force across the door, but the center case takes the whole pull of the latch mechanism at one point. Reinforcing brackets exist to transfer that load into the door rather than leaving it on the baseplate fixings.

On a door that is kicked, barged or propped regularly, the reinforcement is the part that keeps the center case flat against the door. A center case that has started to lift is the early warning of a device that will fail entirely.

What Is Inside the End Cap?

Less than people expect, and that is the point. The end cap closes the hinge end of the rail, anchors the rail to the door and keeps the internal components enclosed.

It is also the part most likely to be damaged, because it sits at the end of a long lever and takes impacts from trolleys, furniture and the wall. Impact resistant versions exist specifically for openings where that is routine.

Does a missing end cap matter?

Yes, on two counts. It exposes the internals of the rail to dirt and interference, and it removes an anchor point, which lets the rail flex when the touchpad is pushed. A device with a flexing rail will eventually stop retracting the latch fully.

How Does the Latch Assembly Work?

The latch is pulled back by the mechanism, held back while the touchpad is depressed, and sprung forward again when the touchpad releases.

Three components do that work: the latch itself, the latch tail that connects it to the mechanism, and the spring that returns it. All three are stocked separately, and the spring is usually the first to go.

A latch that retracts but returns slowly is a spring. A latch that retracts partially is usually the tail or the linkage. A latch that does not move at all with a working touchpad is a center case fault.

Why does the latch group change between devices?

Because the latch has to reach something different. A rim device latches into a strike on the frame. A surface vertical rod device drives rods up and down to latch at the head and sill. A concealed vertical rod device does the same with the rods inside the door. A mortise device drives a lock case in the door edge.

Everything from the touchpad to the center case is largely common across those four. The latch group is where they diverge, which is why diagrams for different device types look similar until the right hand end. Our concealed vertical rod guide covers the most complex of the four.

What Is Dogging and Which Parts Control It?

Dogging holds the touchpad depressed and the latch retracted, so the door becomes push and pull during the hours the building wants it open.

Two methods are common. Hex dogging uses a hex key in a socket to drive a shaft that holds the mechanism. Cylinder dogging uses a keyed cylinder to do the same job, so only key holders can set it.

Can a device be converted between dogging types?

Often, using a conversion kit. Moving from hex to cylinder dogging is a common request on sites that want to stop staff dogging doors informally, and the conversion is a parts order rather than a new device. The reverse conversion also exists.

One point worth confirming first: dogging is not permitted on every opening. A fire rated opening has to latch, so a dogged device on a fire door is a defect rather than a convenience.

Why Does the Touchpad Feel Loose or Noisy?

Usually because of what sits behind it rather than the pad itself.

The touchpad travels every time somebody uses the door, and it stops against the body of the device at the end of that travel. Shock absorbing components take that impact. When they fail, the pad bottoms out metal against metal, which is both the noise people report and a load path into the mechanism that was never intended.

Is a noisy panic bar a safety problem?

Not in itself, but it is a sign of wear that eventually becomes one. A touchpad that has lost its cushioning transmits full impact into the linkage every cycle, and on a busy door that is hundreds of impacts a day. Fixing it at the noise stage is far cheaper than fixing it at the failure stage.

Which Panic Bar Parts Fail Most Often?

In rough order: dogging components, end caps, springs, touchpad cushioning, and latch tails.

None of those require a new device. For the full Von Duprin component listing, our Von Duprin panic bar parts guide and 98 and 99 Series parts guide set the numbers against the groups described here.

What about double doors?

A pair of doors adds the mullion or the overlapping astragal arrangement to the picture, and with it another set of parts that can fail independently of the devices. Our mullion guide covers the removable mullion, which is the most commonly misdiagnosed component on a pair.

How Do You Identify a Part From a Diagram?

Place it in its group first, then match the shape, then confirm the series.

Group narrows the field from fifty items to about eight. Shape narrows it further. The series then decides which of the remaining candidates is the correct number, because the same looking bracket exists in several series with different numbers.

What if the device series is unknown?

Read the stamping, usually found on the baseplate under the rail or on the end cap. If the device has been painted over, the dimensions of the center case and the type of latch group between them identify the family in most cases.

Photographs are worth more than descriptions here. A picture of the device on the door, a second of the latch end, and a third of any visible stamping will usually settle it. Our panic bar selection guide covers how the series are distinguished, and the exit device installation guide covers the mounting arrangement that the diagram assumes. If you are starting from the user side rather than the parts side, our crash bar overview is the better starting point, and panic hardware on commercial doors covers where these devices are required.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A Von Duprin 6211 electric strike enquiry almost always starts the same way. Somebody has a strike in a frame, a number stamped on it that reads 6211, and a part that has stopped doing its job. Then it turns out there are three units sharing that number, and they are not interchangeable.

This guide sets out what the 6211 actually is, how the three variants differ, which parts are supplied separately, and what to establish before ordering anything.

What Is the Von Duprin 6211 Electric Strike?

The 6211 is a heavy duty electric strike from the 6200 Series, designed for single door openings. It gives remote release of a locked door: the lock stays locked, and the strike lets the latch out of the frame when it is signalled.

That distinction matters more than it sounds. An electric strike does not unlock the lock. The lever or knob on the secure side behaves exactly as it did before, and the key still works as it did. What changes is the frame side of the opening, which can now be released from a button, a reader or an access control panel.

What locks does a 6211 accept?

Mortise locks without deadbolts, and cylindrical locksets, provided the latchbolt throw is 3/4 inch. That throw figure is the one to check first, because a latch that projects further will not sit correctly in the keeper and a shorter one may not be held at all.

If you are not certain which family of lock is on the door, our mortise locks versus cylindrical locks guide walks through the visible differences at the door edge.

What Is the Difference Between 6211, 6211AL and 6211WF?

The suffix carries the frame the strike was built for, and with it the depth of the hole the frame needs.

The base 6211 and the 6211AL are both listed for aluminium frames with a 1-11/16 inch backbox depth. The 6211WF is the wood frame unit, and its backbox depth is 4-1/2 inches. That is not a small difference. A WF will not go into a prep cut for an AL, and an AL dropped into a WF cutout will sit in a hole far deeper than it needs.

Do the three share any parts?

Some, and that is where part numbers earn their keep. A single stocked spring kit covers both the 6211 and the 6216, for example, while faceplates are listed per variant. Shared mechanical parts are the reason a strike that has lost its spring tension does not need a new body.

Is the 6211 Fail Safe or Fail Secure?

Fail secure as standard, with fail safe available as an option. In plain terms, remove the power from a fail secure strike and the door stays locked from outside. Remove it from a fail safe strike and the strike releases.

Neither setting affects getting out. Egress happens through the lock on the inside of the door, which is mechanical, so somebody inside can always leave whatever the strike is doing.

How do you set the mode on a 6211WF?

With a slider. Von Duprin lists a fail safe slider as a separate stocked part for the 6211WF, which means the mode is set by a physical component rather than by a different model number.

Two consequences follow. A strike ordered in one mode can be moved to the other without replacing the unit, and a strike behaving unexpectedly on site may simply have been set the other way at some point in its life. Check the slider before condemning the strike.

What Voltage Does a 6211 Need?

The standard listing is 24 VDC, with 12 VDC and 16 VDC available as options. The figure on the strike has to match what the power supply actually delivers at the door, not what it says on the label in the cupboard.

Voltage drop over a long run is the usual culprit when a strike buzzes but does not release. A unit that works on the bench and fails in the frame is rarely faulty. Our electric strike schematic guide covers how the supply, the release device and the strike sit together on a circuit.

Does a fail safe strike draw more current?

In its normal state, yes, because it is held locked by power. A fail secure strike sits idle until somebody releases it. On a site with a battery backed supply, that difference decides how long the supply carries the opening in an outage, so it belongs in the calculation rather than being discovered later.

Which Faceplate Does a 6211 Need?

The listed faceplate for the 6211 family is 4-7/8 inches by 1-1/4 inches. Faceplates are supplied as separate parts, which is useful in two situations: a faceplate damaged by a strike plate removal, and a change of finish on an opening being refurbished.

Faceplates are not universal across the electric strike ranges. A faceplate listed for the 5100 is a 5100 part, not a 6200 part, and the same is true of the 6100. Our Von Duprin electric strike parts guide sets out which part families sit under which series.

What Parts Fail on a 6211 Electric Strike?

The electronics are the part people suspect first and the part that fails last.

A strike lives in a frame, takes the impact of a closing door several hundred times a day on a busy opening, and holds a latch under load whenever somebody leans on the door. The parts that give up reflect that: springs lose tension, keeper surfaces wear, faceplates get bent by levering, and fixings work loose in the frame.

How do you diagnose a 6211 that will not release?

Work from the supply outwards, and measure rather than assume.

Prove the release device is sending a signal. Then measure the voltage at the strike terminals while the release is operated, not at the panel. Then take the load off the strike by pulling the door open slightly and operating the release again, because a latch under side load can hold a keeper that is actually working.

Only when all three have been checked does the strike itself become the suspect. That sequence saves a great many strikes that were never faulty. The same logic applies across the range, and our complete electric strikes guide covers it in more depth.

What Goes Wrong at Installation?

Three things, repeatedly.

The first is backbox depth. The 4-1/2 inch depth of a WF against the 1-11/16 inch depth of an AL is the single most common reason a replacement strike will not go in. Measure the existing cavity before ordering.

The second is latch alignment. The strike is cut into the frame in a fixed position, so the door has to present its latch at the right height. A door that has dropped on its hinges will push its latch against the edge of the keeper.

The third is the mode assumption. A strike fitted fail secure on a door the building expects to release in an alarm is a specification error that will not show up until the day it matters. Our electric strike installation guide covers the sequence in full.

Does the 6211 suit every single door opening?

No. It is listed for mortise locks without deadbolts and for cylindrical locks with a 3/4 inch throw, on a 1-3/4 inch door. A mortise lock with a deadbolt, a different throw, or a pair of doors without a mullion all take the opening outside what this unit was designed for.

Where the opening falls outside those limits, another series usually covers it. Our 6100 Series parts guide and 5100 Series parts guide set out where each one applies.

What Do You Need to Confirm Before Ordering 6211 Parts?

Six things, and five of them are read off the door rather than looked up.

What if the number on the strike is unreadable?

Measure instead. The faceplate dimensions, the cavity depth and the frame material between them narrow the field quickly, and the latch throw on the door confirms whether the opening belongs to this family at all. A photograph of the faceplate and a tape measure reading of the cavity are usually enough for us to confirm the part.

For a broader view of which components exist across the electric strike ranges, our electric strike parts guide lists them by function rather than by model.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

A door that will not latch is one of the most common calls in commercial door hardware, and one of the most commonly misdiagnosed. The lock gets replaced, the latch gets replaced, and the door still bounces back off the frame, because the problem was never in the door at all.

This guide covers how to align a door strike plate properly: how to find the direction of the error, how to correct it, when to move the strike and when to leave it alone, and what changes on a fire rated opening.

What Does It Mean to Align a Door Strike Plate?

Alignment means the latch arrives at the strike opening squarely, enters it without touching the edges, and projects far enough into the frame to hold.

Three dimensions have to be right at once. Height, so the latch meets the cutout rather than the plate above or below it. Depth, so the latch projects into the frame by its full throw with the door closed against the stop. And squareness, so the latch is not entering at an angle that loads one side of the cutout.

Get any one of them wrong and the door reports it differently, which is why the direction of the error matters more than the fact of it. If the strike plate itself is unfamiliar, our strike plate guide covers the component before the adjustment.

Is this the same as adjusting a door strike plate?

In practice people use both phrases for the same job. Adjusting tends to mean small corrections to an existing strike. Aligning covers the whole exercise, including deciding that the strike is in the right place and the door is not.

How Do You Know Which Direction the Strike Is Out By?

Mark the latch and let the door tell you.

Put a line of marker, chalk or lipstick across the face of the latch bolt, close the door normally, and open it again. The transfer mark on the strike plate shows exactly where the latch is landing. A mark above the cutout means the latch is sitting high. A mark below it means low. A mark on the lip means the latch is arriving at an angle or the door is not reaching the stop.

The test takes a minute and removes the guesswork that leads to filing a strike that was never in the wrong place.

What if the mark lands inside the cutout but the door still will not latch?

Then the problem is depth rather than position. The latch is finding the hole but not projecting far enough into the frame to be held. That usually means the door is stopping short, and the gap between the door face and the frame stop is the measurement to take next.

How Do You Align a Door Strike Plate Step by Step?

Work in a fixed order so each step rules something out rather than introducing a new variable.

Start by checking the hinges. Every hinge screw tight, no movement at the leaf, no visible drop at the lock edge. A door that has sagged will present its latch low, and no amount of strike adjustment fixes a hinge.

Next, close the door slowly by hand and watch the latch meet the frame. Slow closing shows you things that normal closing speed hides, including a latch that is clipping the lip before it reaches the cutout.

Then run the marker test and read the direction. Only after that do you touch the strike.

How much can you move a strike plate?

Less than people expect, because the fixing holes constrain it. Small corrections are usually made by filing the cutout edge slightly, packing behind the plate, or replacing the strike with one whose cutout sits differently. Larger corrections mean repositioning the plate and plugging the old screw holes, which is a frame repair rather than an adjustment.

When Should You Shim a Strike Instead of Filing It?

Shim when the latch is not reaching far enough into the frame, or when the door sits loose against the stop with the latch engaged.

A shim strike is a stocked part rather than something to improvise from washers. Packing behind a strike with whatever is to hand changes how the plate sits in its recess, and a plate that is no longer flat will eventually loosen its fixings under impact.

File only when the latch is clipping a cutout edge by a very small amount, and only on a non rated opening. Filing removes material permanently and makes the hole larger in one direction, which is a one way adjustment.

Does the strike box matter?

It does on hollow metal and timber frames. The box lines the cavity behind the plate, stops debris collecting in it, and gives the latch somewhere clean to sit. A missing or crushed box is a common reason a latch enters but does not sit properly, and it is easy to miss because the plate looks correct from outside.

What Is the Deadlocking Plunger and Why Does Alignment Affect It?

It is the small auxiliary pin that sits beside the main latch bolt. When the door closes, the plunger is held in by the face of the strike plate, which in turn stops the main latch being pushed back from outside.

Alignment decides whether that works. The plunger has to land on the solid face of the plate. If it drops into the cutout alongside the latch, it is no longer held in, and the latch loses its deadlocking.

The symptom is specific and easy to recognise. The door latches, feels normal, and can then be pushed open by hand with moderate pressure. That is an alignment fault, not a lock fault, and no new lock will cure it.

How do you check the plunger is landing correctly?

Close the door and look at the gap at the latch edge with a torch, or mark the plunger as well as the latch for the transfer test. If the plunger mark falls inside the cutout outline, the strike needs moving or replacing with one whose cutout is positioned differently relative to the plate face.

Our strike plates and deadlatches parts guide covers how the latch, plunger and plate are supplied as separate items.

How Do You Align a Strike Plate on a Fire Rated Door?

Carefully, and with replacement parts rather than modification.

A fire rated opening is tested and labelled as an assembly. The door, frame, hinges, closer, latch and strike were certified together, and site modification can take the assembly outside what was tested. Filing a strike cutout, enlarging holes or packing behind a plate with uncertified material all fall into that category.

What remains available is correcting the cause rather than the symptom: tightening or replacing hinges, correcting a sagging door, replacing a damaged strike with the correct listed part, and adjusting the closer so the door reaches the stop. Our fire rating guide covers what is and is not permissible on a rated assembly.

What about an accessible opening?

Alignment affects the force needed to open the door, which is a measured requirement on accessible routes. A latch that is binding in a misaligned strike adds resistance that a user has to overcome, so this is not purely a convenience issue. Our door clearance guide covers the dimensional requirements around the opening.

What Do You Do When the Screw Holes Are Worn?

Move to longer fixings into solid material, or plug and redrill.

Worn holes are common on openings that have been adjusted several times, and they produce a strike that creeps back out of position within weeks of being set. Retightening the same screws into the same enlarged holes is the one approach that reliably fails.

Screw packs are stocked as separate items for exactly this reason, and matching the drive type to the existing hardware avoids chewing the heads on the next visit.

Should the strike be reinforced?

On a high traffic opening, or one that has taken a forced entry attempt, a frame reinforcer spreads the load behind the plate instead of leaving it on the frame skin alone. It is worth considering whenever you are already taking a strike off a door that has a history of failing in the same way.

When Is the Strike Not the Problem at All?

More often than the call suggests. Several faults present as a door that will not latch, and three of them live elsewhere.

A door that fails to latch only when the closer brings it shut, and latches every time by hand, is a closer adjustment. Our guide on how to stop a door from slamming covers the latch speed valve that controls the final few degrees, and the hardware troubleshooting guide covers the wider set of symptoms.

What should you record before leaving the opening?

What you changed, and what you measured. Strike alignment is one of the few hardware faults that tends to come back, because the underlying movement in the door or frame continues. A note of the original witness mark position and the correction applied makes the second visit much shorter than the first.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

Quick Summary

Wiegand 26 bit turns up in two very different conversations. One is a specifier asking whether a reader will talk to an existing panel. The other is somebody troubleshooting a door where the reader beeps, the light changes, and nothing happens at the controller.

Both come back to the same thing: what the format is, how the wiring carries it, and where it runs out of room. This guide covers all three.

What Does Wiegand 26 Bit Actually Mean?

It means the reader sends the controller a number made of exactly 26 binary digits, arranged in a defined order that both ends agree on in advance.

The name causes confusion because Wiegand originally described a card technology built around a physical effect in specially treated wire. Those cards are long gone from most buildings. What survived is the wiring interface and the data format, and that is what people mean today.

So a modern proximity or smart card reader is almost never a Wiegand card reader. It is a reader of some other technology that outputs its result in Wiegand format.

How Is a 26 Bit Wiegand Number Structured?

One parity bit, eight bits of facility code, sixteen bits of card number, one parity bit. That order, every time.

The facility code identifies the site or the card batch. The card number identifies the individual credential within that facility code. The two parity bits are a simple error check: the first covers the leading half of the message and the second covers the trailing half.

Why does a card show two numbers on it?

Because printed credentials often show the facility code and the card number separately, and the controller needs both. Enrolling a card using only the number printed largest on the front is a classic cause of a card that reads but is never recognised.

How Does the Wiegand Interface Send Data?

With pulses on two separate lines. One line carries the zeros, the other carries the ones, and the controller assembles the bits in the order they arrive.

Both lines sit high when nothing is happening. To send a zero the reader briefly pulls the first line low. To send a one it briefly pulls the second line low. Twenty six pulses later, across the two lines, the number is complete.

The important consequence is that the conversation only goes one way. The reader talks, the controller listens, and the controller has no way to ask the reader anything or to confirm it is still there.

What does one way communication cost you?

Supervision. If a Wiegand reader is disconnected, smashed or quietly swapped for another one, the controller does not know. It simply stops receiving data, which looks identical to nobody presenting a card.

Which Wires Does a Wiegand Reader Use?

Four as a minimum: two data lines, a positive supply and a common ground. Most installations add a shield or drain, and many readers have extra conductors for the beeper and the indicator so the controller can give the user feedback.

Treat colours as a convention rather than a guarantee, and confirm against the documentation for the specific reader. The ground is the one people get wrong: the reader and the controller have to share a common ground or the data lines have no reference and the reads become intermittent.

How far can a Wiegand reader be from the controller?

The figure usually quoted is around 500 feet, and it is a guideline rather than a hard edge. Cable type, conductor size, the supply voltage and electrical noise along the route all move it. If a reader is right at the limit and behaving unpredictably, distance is a reasonable first suspicion.

What Are the Limits of 26 Bit Wiegand?

Three, and they build on each other.

The number space is small. Sixteen bits of card number is 65,536 values, and eight bits of facility code is 256. A large organisation can exhaust that, and more importantly two unrelated sites can end up holding cards with identical facility code and number.

There is no security in the format. The number travels in the clear along two wires, and anything that can read those wires can capture it and replay it.

And there is no supervision, as above. The controller cannot tell a working reader from a missing one.

Why Do Facility Codes Matter So Much?

Because they are the only thing separating your card population from somebody else's, and there are only 256 of them.

On a single site with one facility code, the system is effectively checking a 16 bit number. If a neighbouring organisation happens to hold the same facility code, a card from their building carries a number your controller may recognise as valid.

That is why larger formats exist. More bits means a bigger number space and a much lower chance of collision, at the cost of needing both ends to agree on the longer format.

Can you mix formats on one system?

Sometimes, if the controller supports multiple formats simultaneously, but it is worth avoiding where you can. A site running several formats is harder to troubleshoot, because a card that does not work might be unenrolled, might be the wrong format, or might be a format the reader is not configured to pass through.

What Is OSDP and Should You Move to It?

OSDP is the open supervised device protocol, and it was designed specifically to fix what Wiegand cannot do.

It runs over a two wire serial connection rather than separate data lines. It is bidirectional, so the controller can query the reader and the reader can report its status. It supports supervision, so a missing reader raises an alarm rather than going quiet. And it supports encryption between reader and controller.

The honest answer on migration is that it depends on the panel. Many readers support both, so the reader is rarely the obstacle. The controller and the head end software usually decide whether it is practical.

Does the Reader Technology Change the Wiegand Output?

Not the format, no. A keypad, a magnetic stripe reader and a smart card reader can all present a 26 bit Wiegand message to the same controller input.

Where both a card and a code are needed, a combined module handles the two inputs and sends the result on the same interface.

Our proximity card reader guide covers the reader side in detail, including mounting and multi technology options.

Why Do Wiegand Readers Stop Working?

That last row catches people regularly. If anything on the door side is wired through the moving leaf, the crossing fatigues long before the devices do. Our electric hinge guide covers it.

What Should You Confirm Before Ordering a Reader?

Six things. The format the controller expects, including the bit count. The credential technologies the site uses now and plans to use. Whether a keypad is required. The mounting position, which decides the physical size. The voltage available at the door. And whether the system is moving to a supervised protocol, because that may change the reader choice today.

For the wider system, our access control hardware integration guide covers how the reader, lock, door position switch and request to exit device work together, and the request to exit sensor guide covers the exit side.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If you know the panel but not which reader module suits it, contact us with the format the controller expects, or browse Schlage replacement parts and the electric strike parts section.

Quick Summary

Detex parts enquiries usually arrive with a photograph and a number that does not quite match anything. The range is wide, the families overlap in what they do, and the same looking device can belong to two different series.

This guide is the map. It covers what each family is for, how to tell which one you are standing in front of, where the parts live, and what to confirm before ordering.

What Does Detex Make, and Where Does It Fit?

The common thread across the range is controlling an exit rather than simply locking a door.

Plenty of manufacturers make a device that lets people out. Detex is specified where the building also needs to know about it, delay it, alarm it or power it. That is why exit alarms, delayed egress and exit control locks sit alongside conventional exit devices in the same catalogue.

The second cluster is the electrified side of an opening: low energy operators, touchless activation, power transfers and request to exit sensors. Those turn up on accessible entrances and on access controlled doors regardless of what brand the lock is.

Does that affect how you order parts?

Yes, because it means a Detex part might be on a door with no other Detex hardware on it. A power transfer or a request to exit sensor is specified for the opening, not for the brand of the lock, so do not assume the family from the device next to it.

Which Detex Family Is on Your Door?

Where the device is an exit device rather than an alarm or an operator, the configuration still has to be settled: rim, surface vertical rod, concealed vertical rod or mortise. Our concealed vertical rod guide and rim exit device guide cover how to tell them apart.

What Is the Value Series?

The Value Series is a range covering exit devices and the alarm and egress functions built around them.

Within it you will find the V40 Series devices, an exit alarm range covering several model letters, and a delayed egress range. They share a design language and a parts approach, which is why identifying the series matters more than identifying the individual model at first.

What does the exit alarm range do?

It sounds locally when the door is used. The door still opens immediately, which is the point: the alarm is there to tell the building the exit has been used, not to stop anyone leaving.

And the delayed egress range?

Delayed egress holds the door for a defined period after somebody pushes it, then releases. It is a code controlled function with conditions attached, including automatic release on alarm and on power loss, and it is not permitted on every door.

Our guide to delayed egress covers the rules, and what an exit alarm is covers the simpler case.

What Is Advantex and How Does It Differ?

Advantex is the range where the device and its electronics are designed together rather than bolted on, covering the 10 and 40 Series openings.

In parts terms that shows up as boards and dogging assemblies that are specific to the range and to the configuration. An Advantex dogging assembly for a mortise device is a different part from one for a surface vertical rod device, even on the same series.

The electronic side is serviceable in its own right rather than being sealed into the device.

What Are Exit Control Locks?

Exit control locks are surface mounted units fitted to doors that exist for emergencies and should not be used routinely.

They secure the door and alarm when it is used, and the range includes two point and three point locking versions along with weatherized variants for exterior openings. The three point versions engage at more than one place on the door, which suits wider leaves and exposed positions.

The usual application is a fire exit at the back of a building that keeps being used as a shortcut. Our exit control lock parts guide covers the range at component level.

Do they stop people getting out?

No, and they must not. The door opens when it is pushed. What changes is that the building finds out, which is almost always the actual requirement behind the request.

What Detex Access and Egress Electronics Exist?

Four groups turn up repeatedly, and they are often specified on doors with no other Detex hardware.

Low energy powered operators for accessible entrances, in single, double and dual egress configurations. Touchless and wireless activation kits that go with them. Power transfers and energy transfer hinges that carry wiring from the frame into a moving leaf. And request to exit sensors, in both infrared and microwave versions.

Each of these is covered in its own guide: automatic door openers, electric hinges and power transfers, and request to exit sensors.

Which Cylinders Do Detex Devices Take?

Detex devices use cylinders like any other exit hardware, and the range includes its own mortise cylinders, rim cylinders and interchangeable core housings so a site can key the hardware into its existing system.

The decision is the same one you face on any device. A mortise cylinder drives a cam, a rim cylinder drives a tailpiece, and the device dictates which it takes. Interchangeable core housings are specified where the building wants to rotate keys without removing hardware from the door.

Should the device be keyed alike with the rest of the site?

Usually the answer depends on who holds the key rather than on the hardware. Emergency exits and plant doors are often deliberately on a restricted key that general staff do not carry, while a run of similar doors in one department is easier to manage keyed alike.

Our mortise cylinder and rim cylinder guide covers the mechanical side of that choice, and the keyed alike locks guide covers when to use one key across several doors.

How Do Detex Part Numbers Work?

Mostly numeric, often six digits, frequently with a suffix after a dash. The suffix is where the configuration lives, and it is the part people drop when writing a number down.

Two parts differing only in a suffix can be for completely different configurations, so copy the number in full including anything after the dash.

What Fails Most Often on Detex Hardware?

The pattern across the electrified items is consistent: the device is usually fine and the thing feeding it is not. Prove power and signal before ordering electronics.

How Do You Identify a Detex Part Before Ordering?

Five pieces of information cover almost every order.

The range, from the stamping or the model plate. The configuration, read off the door rather than assumed. Whether the device includes alarm or delayed egress functions, because that changes the internal parts entirely. The handing, where it applies. And the finish, matched to the existing hardware.

On a device with electronics, add one more: whether the fault is mechanical or electronic, because that decides whether you are ordering a dogging assembly or a board.

Start from the Detex parts section, or the Detex exit alarm hardware parts guide if the device alarms. The exit alarm parts section and the parts by brand index cover the wider catalogue.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the model plate has worn away and all you have is a shape, send a photograph of the device and the door through our contact page and we will narrow the range before you order.

Quick Summary

A door with access control on it has an awkward problem. The reader knows who came in, but nothing tells the system who is going out, so every normal departure looks identical to somebody forcing the door.

Request to exit hardware solves that. This guide explains what the sensor is actually doing, how the motion sensing versions differ from the switch versions, where they go, and why so many of them end up being blamed for faults that are not theirs.

What Is a Request to Exit Motion Sensor and Why Is It Fitted?

It is a detector mounted above the door on the inside, aimed at the floor area somebody crosses on their way out. When it sees movement it closes a contact, and that contact tells the access control panel to expect the door to open.

The signal usually does two things. It suppresses the alarm that would otherwise be raised by the door position switch, and it creates a proper exit record in the log.

The reason it exists rather than just wiring a button is friction. A sensor asks nothing of the user, which matters on doors people go through with full hands, and on accessible routes where pressing a button may not be realistic.

What Happens If a Door Has No Request to Exit Signal?

Every legitimate exit is reported as a door forced open, and within a week nobody is reading the alarms any more.

That is the real cost of a missing request to exit signal. It is not that the door fails to work, it is that the monitoring becomes noise and a genuine forced door stops standing out from the thirty false ones that day.

The second effect is on records. Without an exit signal the system has entries but no departures, so occupancy reporting and roll call information are unreliable. Our door position switch and request to exit guide covers how the two signals work together.

Motion Sensor or Switch: Which Type of REX Do You Need?

They answer different questions, and on some doors you want both.

A switch inside the hardware signals that the device has actually been operated. It is precise. Nothing reports an exit unless somebody physically works the lever or pushed the bar.

A motion sensor signals that somebody is approaching. It is earlier, which matters when the panel has to release a lock before the user reaches the door, and it is less precise, because approaching is not the same as leaving.

On exit devices, the switch version is often built into the bar itself rather than added separately.

How Does a PIR Request to Exit Sensor Work?

Passive infrared sensors detect the heat a human body gives off, and specifically detect it moving across the detection pattern.

The word passive matters. The sensor emits nothing. It simply watches for a change in the infrared energy reaching it, which is why these units draw very little power and why they do not interfere with anything else.

What does a PIR sensor struggle with?

Moving air at a different temperature, which is why a sensor near a heater, an air conditioning outlet or a draughty vestibule misbehaves. Direct sunlight across the detection area causes the same problem. So does a person approaching very slowly, because the sensor is watching for change rather than presence.

When Is a Microwave Sensor the Better Choice?

When the environment defeats infrared, or when you need detection through something.

Microwave sensors transmit a signal and watch for the shift that comes back from a moving object. They are not affected by air temperature, they are less troubled by sunlight, and they detect motion rather than heat.

The trade is containment. Microwave energy does not respect the boundaries you would like it to, so a badly set unit detects movement on the other side of a partition or in the corridor beyond. Setting the sensitivity properly is more of a job than it is with infrared.

Where Should a Request to Exit Sensor Be Mounted?

Above the door, on the secure side, aimed down at the area a person crosses immediately before reaching the door.

Three mistakes account for most poor installations. Mounting the sensor so the pattern reaches past the door into a corridor, which means passers by trigger it. Mounting it so the pattern does not reach far enough, so the lock does not release until the user is already pulling the handle. And mounting it where the door itself swings through the detection area, so the door triggers the sensor on its way closed.

How do you check the coverage is right?

Walk it. Approach the door at normal walking pace from the direction people actually use and note where the sensor picks you up. Then walk past the door without stopping and confirm it does not. Both tests matter, and most units are set using only the first.

Can a Motion Sensor Release a Magnetic Lock on Its Own?

This is the question that matters most and the one with the most careful answer.

Codes treat electrically locked egress doors as a special case, and sensor release of those doors carries specific conditions, which typically include a manual release device and a requirement that the lock fails unlocked on loss of power. Exactly what is permitted, and on which doors, is decided by the authority having jurisdiction.

So the honest answer is that a sensor can be part of a compliant arrangement, and is not by itself a substitute for a mechanical means of escape. Treat the sensor as one element of a designed egress solution, not as the solution.

Our electromagnetic lock parts guide covers the egress rules that apply to maglocks, and the delayed egress guide covers the case where the door is deliberately held.

How Is a Request to Exit Sensor Wired In?

Two connections matter: power to the sensor, and the contact back to the panel.

Power is usually taken from the same supply feeding the lock and the reader at that door. The contact is a dry relay output, and the panel expects it in a particular state, either normally open or normally closed. Getting that backwards produces a door that is permanently in request to exit, which suppresses the alarm the whole time and quietly removes the monitoring you installed the sensor to provide.

Why do these doors fail intermittently?

More often than not it is not the sensor at all. If anything electrified sits in the moving leaf, the wiring has to cross from the frame to the door, and that crossing is the part that fatigues. A fault that changes with door position is almost always the transfer route rather than the device. Our electric hinge guide covers why.

The other common cause is a supply that measures correctly at rest and sags when the lock operates. Measure voltage at the device while the door is actually working, not with everything idle.

Why Do Request to Exit Sensors False Trigger?

The pattern across all of these is that the sensor is usually reporting exactly what it sees. Before replacing one, prove what is moving in the detection area.

What Do You Need to Confirm Before Ordering?

Six things settle the order. The technology, infrared or microwave, based on the environment. The output type the panel expects, and whether it needs a normally open or normally closed contact. The voltage available at the door. Whether a timer or adjustable hold is required. The mounting position and the coverage the opening actually needs. And whether the door is part of an electrically locked egress arrangement, because that changes what is permitted.

If you are specifying the whole opening rather than replacing one sensor, our access control hardware integration guide covers how the reader, the lock, the door position switch and the request to exit device fit together, and the electric strike parts section covers the locking side.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If a door is raising forced alarms on every exit and you are not sure what is fitted above it, contact us with a photograph of the head of the opening, or browse Detex parts for the sensor range.

Quick Summary

Someone needs to take a lever off a door, finds no screws anywhere, and concludes the lock is riveted together. It is not. The fixing is deliberately hidden, and there is a specific tool for it.

This guide covers what that tool is, what the hidden catch actually consists of, what to do when the lever will not come off even with the tool, and which of the other service tools you are likely to need alongside it.

What Is a Schlage Lever Removal Tool?

It is a spanner wrench: a small flat tool with a pin or a formed end that reaches into a hole in the lever or rose and depresses the catch holding the trim on.

Press the catch, pull the lever, and it comes away from the chassis. No force, no levering, no screwdriver damage to the rose.

Why is the fixing hidden in the first place?

Security. If a lever could be removed with a screwdriver from the corridor, anybody could take the trim off the unsecured side of a locked door and reach the mechanism. Hiding the catch and requiring a specific tool removes that option.

It also keeps the door looking right. Visible fixings on a lever rose age badly and collect dirt, and on a reception door that matters.

How Does the Hidden Catch Actually Work?

A small spring loaded button sits in the lever or the sleeve behind it, projecting into a recess. While it is projecting, the lever cannot slide off. Depress it and the lever is free.

That button is a stocked part in its own right, because it is small, it is sprung, and sprung parts wear.

On some assemblies the button works with a plunger behind it rather than sitting directly in the lever, and that plunger assembly is listed separately again.

How Do You Use a Spanner Wrench on a Lever?

The sequence is short, and the whole skill is in finding the hole.

Look at the underside of the lever where it meets the rose, and at the rose itself. There will be a small hole, often less than three millimetres across, easy to mistake for a blemish in the casting. Insert the tool, press firmly and squarely until you feel the catch give, then draw the lever straight off the spindle while keeping the pressure on.

What if you do not have the tool?

Get one before you start. A small screwdriver or a nail will sometimes depress the catch, and it will also scar the rose, round off the hole and occasionally push the button out of position so the lever will not relock onto the spindle afterwards.

The tool is inexpensive next to a replacement lever assembly, and far cheaper than a chassis.

When Do You Actually Need to Take a Lever Off?

More often than people expect, and rarely because the lever itself is the problem.

Trim comes off to reach the chassis, to change a cylinder on some functions, to convert a knob to a lever, to replace a worn rose, to swap a handing, and to fit or service an electrified component inside the lock. On a refurbishment it comes off simply so the door can be painted properly.

Is it worth removing trim just to diagnose?

Yes, on any door where you are about to spend money. Operating the latch directly with the trim off takes two minutes and tells you immediately whether the lever, the spindle or the chassis is at fault. Without that step you are ordering on a guess, and trim and chassis parts are very different amounts of money.

How Do You Keep Levers From Working Loose in the First Place?

Most loose levers are not a parts problem, they are a load problem. People pull doors shut by the lever, lean on it while talking, and hang bags from it, and the trim takes that side load thousands of times a year.

Three things reduce it. A door closer set so the door shuts properly on its own, which removes the reason to pull it closed by the handle. A pull on the opposite face where people need something to grab. And catching a loose rose early, because a rose that is allowed to move will wear its seat in the door face and then nothing will stay tight.

Where a door is genuinely abused rather than simply busy, the honest answer is heavier trim rather than more frequent tightening. A door that has had the same lever retightened three times in a year is telling you something the maintenance log will not.

What Is the Difference Between a Removal Tool and an Emergency Key Tool?

They get confused constantly because both are small, flat and kept in the same drawer, and they do completely different jobs.

An emergency key tool operates a privacy function from the outside. On a restroom or changing room door the inside has a turn and the outside has a small slot or hole, and the tool releases that lock so somebody can be reached.

Every building with privacy function doors should have these accessible to staff, not locked in a maintenance store. That is the entire point of the function.

Which Other Service Tools Do You Actually Need?

Three come up repeatedly once you are working on commercial trim.

A cylinder nut tool, for tightening or releasing the retaining nut behind exit device trim where there is no room for anything else.

Hex keys in the right sizes, because dogging on exit devices and several arm fixings on closers use them, and a rounded socket is a part replacement rather than an annoyance.

And a control key if the site runs interchangeable cores, because without it a core swap becomes a destructive job. Our Schlage lock cylinder replacement guide covers that.

Does the Tool Differ Between Schlage Series?

Yes, enough to matter. The catch position, the hole size and the shape of the engagement differ between families, so a tool that works perfectly on one series may not reach on another.

This is the main reason to check the tool against the series you are working on rather than buying the first one you find. A tool that nearly fits is the thing that rounds out the hole.

Our guides to the L Series parts diagrams and the 09-506 outside lever show how the trim assembles on those families.

What Should You Check Once the Lever Is Off?

Four things, while you have access that you will not have again without repeating the job.

The spindle, for rounding or twist. The button and plunger, for free movement. The rose seat in the door face, for wear that will let the new trim work loose. And the chassis itself, by operating the latch directly, to confirm the problem really was the trim.

That last check saves the most time. If the latch is sluggish with the trim removed, fitting a new lever will not fix anything. Our Schlage door knob parts guide covers which trim components are separately available.

How Do You Order the Right Tool and Parts?

If a site has more than a handful of doors on one family, buy the tool once and keep it with the keys rather than ordering it again on every call. Browse Schlage replacement parts, or the Schlage lock parts overview for the wider range.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If you cannot find the hole on an unfamiliar lever, send a close photograph of the lever and rose through our contact page and we will tell you which tool it takes, or browse cylindrical lock parts and mortise lock parts.

Quick Summary

LCN 4642 enquiries almost always start the same way. Someone has a unit at the head of an accessible entrance, it has stopped behaving, and the only identification is a number stamped on the body.

This guide covers what the 4642 is, how its parts are numbered, which assembly to suspect for which symptom, and what to confirm before ordering. Everything here is at part level, because that is how these units are repaired.

What Is the LCN 4642 and How Does It Differ From a Door Closer?

The 4642 sits in the Auto Equalizer family. That means it is a low energy power operator: it opens the door under power when somebody activates it, and it controls the door closed afterwards.

An ordinary door closer only does the second half of that job. It never opens the door, it only manages the return. The operator does both, which is why it has a controller, a power supply and activation inputs that a closer has no equivalent for.

That difference is the reason the parts list contains electrical assemblies alongside hydraulic ones, and the reason a fault can sit on either side.

Why is it called an equalizer?

The family name comes from what the unit does for the user: it removes the physical effort of opening the door, so a person who cannot manage the opening force of a conventional closer can still use the entrance independently.

Which Cylinder Assembly Does a 4642 Take?

The cylinder assembly is the hydraulic heart of the unit and the most commonly ordered part. There is more than one version, so this is where confirming before ordering actually saves money.

There is also a version built with a concealed input and output switch. That switch provides signalling to and from the operator without anything visible on the outside of the unit, and it is specified where the opening is integrated with other systems.

What is the difference between a cylinder assembly and a cylinder only?

The assembly includes the surrounding components the cylinder mounts with. The cylinder only item is the bare hydraulic unit, for cases where everything around it is sound and being reused.

What Does the Controller Do, and When Does It Need Replacing?

The controller is the electronics. It takes the activation signal, decides what the operator does, and sequences the opening and closing.

Controller faults look different from hydraulic faults. A failed controller typically means the door does nothing at all when activated, or behaves erratically and inconsistently. A failed cylinder means the door still responds but the movement itself is wrong: too fast, too slow, or uncontrolled on the way closed.

How do you tell a controller fault from an activation fault?

Test the activation device separately. If a push plate or sensor is not sending a signal, the controller is behaving correctly by doing nothing. Prove the signal arrives before condemning the electronics, because activation devices and their wiring fail far more often than controllers do.

What Mounting Parts Does the Unit Need?

The mounting plate assembly carries the unit and transfers its load into the frame or the door. It is a 4640 part because the mounting arrangement is common across the family.

Fixings are listed separately too, including the controller screw. On a unit that has been opened and closed repeatedly for service, replacing fixings alongside the assembly is cheap insurance.

What Symptoms Point to Which Part?

The pattern worth remembering is that the activation side fails more often than the operator, and the mechanical side of the opening fails more often than either. Our commercial door hardware troubleshooting guide covers the wider sequence.

What Accessibility Rules Apply to a Low Energy Operator?

Two sets apply at the same time, and they are easy to confuse.

The operator itself is governed by the standard covering low energy power operated doors, which sets how slowly it must open, how slowly it must close, and the limits on the force it may apply.

The opening is separately governed by the accessibility requirements that apply to any accessible door: clear width, maneuvering space, hardware height and so on. Fitting an operator does not remove those, although it does solve the opening force question entirely. Our ADA door clearance guide covers that side.

Does the unit still need to control the door closed?

Yes. A powered operator takes over the closing function from the closer, so the closing behaviour has to be correct in its own right. That is why a cylinder fault on these units shows up as a door that slams or drifts rather than one that will not open.

What Activates a 4642, and Does That Change the Parts List?

Activation is a separate decision from the operator, and it has its own failure modes and its own parts.

Push plates, touchless wave sensors, bollard mounted actuators and wireless transmitters all do the same job. What changes is where the user has to be standing and what they have to touch, which matters a great deal for an accessible entrance.

Because activation is separate, an activation change rarely touches the operator at all. Our commercial door operators guide and the door operator parts guide cover the components across the whole powered opening.

Can a 4642 Be Serviced in Place, or Does It Come Off the Door?

Most of the work happens in place. The cover comes off, the assemblies inside are accessible, and the cylinder, controller and fixings can all be changed without taking the unit down.

The unit comes off the door when the mounting plate is being replaced, when the substrate behind it has given way, or when the arm geometry has to be reset after structural work on the frame. Those are the jobs worth planning for, because they need the opening out of service for longer.

What should you do before opening the cover?

Isolate the power and confirm it is off at the unit, not just at the switch. These are powered operators with a motor and a controller inside, and the sequencing logic can move the door when you are not expecting it.

Then open and close the door by hand with the arm disconnected. It takes a minute and it rules out the most common cause of complaints about powered doors, which is that the door itself has gone stiff and the operator is being blamed for it.

How Long Should an Auto Equalizer Last Between Service Visits?

Longer than most of them get, is the honest answer. These units are normally fitted on main accessible entrances, which means high cycle counts, and they are often the last thing anybody inspects.

The realistic pattern we see is that the hydraulic side fails gradually and the electrical side fails suddenly. A cylinder gives warning for weeks as the closing swing gets less controlled. A controller or an activation device tends to work one morning and not the next.

That difference is useful for planning. If somebody reports the door closing harder than it used to, that is a scheduled repair. If the door stops responding entirely, the opening needs attention the same day, because an accessible entrance that does not open is an access problem rather than a maintenance one.

What Should You Confirm Before Ordering 4642 Parts?

If the unit is one of the other Auto Equalizer variants rather than a 4642, the Auto Equalizer parts guide covers the wider family, and the Senior Swing parts guide covers the heavier operator range.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the stamping is unreadable or you are unsure whether the cylinder has the concealed switch, contact us with a photograph of the unit with the cover off, or browse LCN parts and the door operator parts section.

Quick Summary

The ND80 is one of the most specified locks in commercial buildings and one of the most misunderstood. Half the service calls about it are not faults at all. The outside lever does not turn because it is not supposed to turn.

This guide covers what the function actually does, how it compares with the other ND functions, what the electrified versions change, and how to convert or order one correctly.

What Is the Schlage ND80 and What Does the Function Do?

The ND80 is a cylindrical lockset from the ND Series with the storeroom function. Storeroom means the door is locked from the outside at all times, and only a key gets you in.

The outside lever does not rotate. It is rigid, deliberately, so there is no mechanism to force and nothing for a user to misread. Turning the key retracts the latch for that entry and the door relocks behind them. There is no way to leave it unlocked by accident.

The inside lever is always free. Push the door, turn the lever, and you are out. That is not a convenience, it is an egress requirement on the overwhelming majority of commercial doors.

What is a deadlocking latch and why does it matter here?

A deadlocking latch has a small auxiliary plunger beside the main latch bolt. When the door is closed the plunger is held in by the strike, and that stops the main bolt being pushed back from outside. Without it, a storeroom function door with a permanently locked lever would still be vulnerable to the oldest trick there is.

How Does ND80 Differ From the Other ND Functions?

Function codes are the whole language of commercial locks, and the ND number is what carries the function.

The distinction people most often get wrong is storeroom against classroom. A classroom function can be left unlocked. A storeroom function cannot. On a door that must never be found open, that difference is the whole specification.

Our commercial lock function codes guide works through the full set and how the codes are read.

Where Should an ND80 Be Specified?

Anywhere the door has to be secure by default and nobody should be able to change that from the corridor.

Plant rooms, electrical intake rooms, server rooms, stock rooms, cleaners' cupboards and any space holding equipment or material that walks. The common thread is that occupancy is occasional, access is by key or credential, and leaving the door unlocked is never the intended state.

Where is it the wrong choice?

On a door people pass through regularly in both directions. A storeroom function on a busy internal door means every single entry needs a key, and the predictable result is somebody wedging it open, which defeats the lock entirely.

That failure pattern is worth naming because it is so common. If a storeroom door is permanently propped, the answer is usually the wrong function rather than badly behaved staff.

What Do ND80EL and ND80EU Mean?

Both are electrified versions of the same storeroom function, and the two letters describe what the electricity does.

The EL version is electrically locked, described as fail safe. Power holds the outside lever locked, and when power is removed the lever becomes operable.

The EU version is electrically unlocked, described as fail secure. Power releases the outside lever, and when power is removed the door stays locked.

Does electrifying the lock change egress?

No, and this is the point that reassures people. On both versions the inside lever stays mechanically free. Whatever the electronics are doing, and whatever the power is doing, somebody inside can always get out by turning the lever.

Which One Do You Need: Fail Safe or Fail Secure?

This is decided by what has to happen to that specific door during a power failure, and it is a question for the people responsible for the building rather than for whoever is ordering the part.

Get this wrong in either direction and the consequences are real: a store room that unlocks itself during an outage, or a door on an escape route that locks people on the wrong side of it. Our access control integration guide covers how these choices sit alongside the rest of the system.

Can You Convert an Existing ND Lock to ND80?

Often, yes, and it is far cheaper than replacing the lockset.

A conversion kit changes the function of an existing ND lock to storeroom. The chassis stays in the door, the trim stays, the keying stays, and the behaviour changes.

Conversion is the right call when a room changes use, when a classroom function door keeps being left unlocked, or when a site is standardising its functions. It is the wrong call when the chassis itself is worn out.

What Parts Are Serviceable on an ND80?

Most of it. These locks were designed to be repaired rather than discarded, which is a large part of why they are specified in institutional buildings.

Levers, roses, hubs, springs, latches, strikes and cylinders are all separate items. The chassis is the part you replace last, not first.

Does an ND80 Need a Particular Strike?

It needs one that lets the deadlocking plunger do its job, and that is a more specific requirement than it sounds.

The plunger has to land on the solid face of the strike, not drop into the latch hole alongside the main bolt. If the strike is misaligned, or if the hole is oversized from a previous repair, the plunger falls into the cavity and the deadlocking feature stops working. The door still latches and still feels secure, and it is no longer resisting anything.

This is worth checking on any storeroom door, because it is invisible from the corridor. Close the door, then try to push the latch back with a thin piece of card against the bolt. If it moves, the plunger is not engaging.

What about the lip length?

The lip is the curved part of the strike that guides the latch in. Too short and the latch catches on the frame, too long and it projects into the opening where people and trolleys will find it. On a storeroom door that gets used with hands full, a correctly sized lip is the difference between a door that latches and one that gets left ajar.

Our guide to strike plates, lip length and alignment covers how to measure for the right one.

What Goes Wrong With an ND80?

On the electrified versions, remember the lock sits in a moving door, so the wiring has to cross from the frame. Our electric hinge guide covers that route and why it causes most intermittent faults.

How Do You Order the Right ND80?

Six details, and they are all readable at the door or from the schedule: the function you need, whether it is mechanical or electrified, fail safe or fail secure if electrified, the lever design, the finish, and the handing.

Cylinders are usually a separate line. A lock supplied less cylinder lets the site key it to its own system, which is almost always what a building with a key hierarchy wants. Our Schlage lock cylinder replacement guide covers that side.

If you are weighing the ND Series against the lighter range, the Schlage ALX Series guide sets out where each one belongs. For the parts themselves, browse cylindrical lock parts and Schlage replacement parts.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If you are not certain which ND function is on the door, describe how the levers and key behave through our contact page and we will identify it before you order a kit or a lock.

Quick Summary

Most Schlage cylinder replacements go wrong in the same way. The new cylinder arrives, it drops into the hole, the key turns, and nothing happens. The cylinder is fine. What is missing is the piece between the cylinder and the lock.

This guide works through the whole decision in order, so you order a cylinder that turns, fits your keys and matches the door the first time.

What Does Replacing a Schlage Lock Cylinder Actually Involve?

It depends entirely on whether the lock uses an interchangeable core or a conventional cylinder, and those two jobs are not comparable.

On an interchangeable core lock the cylinder is a plug that drops out when a control key is turned. No tools, no dismantling, under a minute. On a conventional cylinder the lock usually has to be partly taken apart, the cylinder unscrewed or released, and the tailpiece transferred or replaced.

So the first question is never which cylinder to buy. It is which system you are standing in front of.

How can you tell at a glance?

Look at the face of the cylinder. An interchangeable core has a distinctive figure of eight or keyhole shaped profile, with the core sitting inside a surrounding housing and a visible seam between them. A conventional cylinder is a single round or shaped face with no seam.

Which Type of Schlage Cylinder Is in Your Lock?

Three families cover almost everything in service, and they are not interchangeable with each other.

Why does the distinction matter so much?

Because it decides whether a replacement is a one minute job for a caretaker or a service call. Buildings that expect to rekey often are built around interchangeable cores for exactly that reason.

What Is the Difference Between a Core and a Cylinder Housing?

The core carries the pins and the keyway. The housing is the fixed part that stays in the lock and accepts the core.

Replace the core when keys are lost, when the keying changes, or when the plug itself is worn or damaged. Replace the housing only when the housing is damaged, which is rare, or when the lock is being converted to accept cores for the first time.

Where you are weighing cylinder types across a whole site rather than fixing one door, our mortise cylinder and rim cylinder guide covers which type belongs in which lock.

How Do You Remove an Interchangeable Core?

With the control key, and only with the control key. It is a separate key from the operating key and it does one job.

Insert the control key, turn it a small amount, and the core lifts out on the key. The operating key will not do this, no matter how it is turned, because the control key engages a different shear line inside the core.

What if nobody can find the control key?

Then the core has to be removed destructively or the lock dismantled, and it becomes a locksmith job rather than a maintenance one. This is the single most common reason an interchangeable core site loses the advantage it paid for, so it is worth knowing where the control keys are before you need them.

Our Schlage key systems guide covers control keys and how they sit in a keying hierarchy, and the master key system design guide covers the structure above them.

Why Does the Tailpiece Decide Whether the Cylinder Works?

Because the cylinder does not touch the latch. Turning the key turns the plug, the plug turns the tailpiece, and the tailpiece reaches back into the lock to move the mechanism. If that connection is the wrong length or the wrong shape, the key turns and nothing moves.

Three things vary: length, which has to suit the door thickness and the lock depth, profile, which has to match the slot in the lock, and orientation, which on some locks is handed.

Cam or tailpiece: which does your lock use?

Mortise cylinders drive a cam, a flat plate on the back of the cylinder that sweeps round and operates the lock case. Rim cylinders and most cylindrical locks use a tailpiece, a flat bar that projects backwards. Both do the same job in different shapes, and neither substitutes for the other.

Do You Need to Match the Keyway?

If you want existing keys to work, yes, and this is where cylinder orders most often fail silently.

The keyway is the shaped slot the key slides into. Keys cut on one keyway will not enter a cylinder of another, even when both are Schlage and both look similar. A site that has standardised on one keyway needs every new cylinder on that keyway or the key stops being a master key in any useful sense.

If you do not know the keyway, do not guess. The site key records hold it, and so does the stamping on the key itself in many systems.

What Does Less Cylinder or Less Core Mean on a Product?

It means the item is supplied deliberately without a cylinder, so you can fit one keyed to your own system.

This catches people out when a lever or trim arrives and appears to be missing a part. It is not missing. A building with an established key system almost always wants hardware supplied this way, because a factory fitted cylinder on the wrong keyway is worse than no cylinder at all.

When ordering less cylinder hardware, order the core or cylinder at the same time, and confirm the keyway with whoever holds the key records.

Should you rekey the existing cylinder instead of replacing it?

Often, yes. If the cylinder is mechanically sound and the only problem is that a key has gone missing, rekeying the existing cylinder to a new combination is cheaper and keeps the keyway and the tailpiece exactly as they were.

Replacement earns its place when the plug is worn so that the key sticks or turns loosely, when the cylinder has been attacked, when the keyway itself has to change, or when the lock is being brought into a key system it was never part of. On an interchangeable core site the question rarely arises, because swapping a core is already the cheap option.

Which Finish Should You Order?

Match what is already on the opening rather than what looks right in a photograph. Finishes are coded, the codes are consistent across manufacturers, and the code is what you order by.

The practical risk is a cylinder that works perfectly and looks obviously newer or a different shade than the trim around it. On a single back door that may not matter. Across a reception area it does.

Our commercial door hardware finish guide lists the codes and what they correspond to.

What Goes Wrong When People Replace a Cylinder?

What Do You Need to Confirm Before Ordering?

Five things, all readable at the door or from the records. Collect them and the order is straightforward.

The lock series and function. The cylinder family, conventional or interchangeable core. The tailpiece or cam the old cylinder used. The keyway. The finish code on the existing hardware.

If the old cylinder is still in hand, keep it. Nothing confirms a tailpiece faster than putting the two side by side. For the wider parts picture, browse Schlage replacement parts, the Schlage lock parts overview or the thumbturn cylinder guide if the inside of the door has a turn rather than a key.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If you have the old cylinder but no part number, contact us with a photograph of the back of it including the tailpiece or cam, and we will identify what you need.

Quick Summary

A knob comes loose, a rose starts spinning, a knob snaps off in someone's hand, and the question is always the same: can we just replace that bit, or does the whole lock have to come out?

Almost always you can just replace that bit. This guide covers which parts exist, how they relate to each other, and the four things that decide the part number.

What Counts as a Schlage Door Knob Part?

Everything from the face of the door outwards, plus the spindle that connects through to the lock. The lock case or chassis is a separate conversation, and in most knob failures it is untouched.

That is the useful insight, because the chassis is the expensive part. A knob that has worn, loosened or been snapped off is trim damage, and trim is stocked at component level.

Is a door knob part the same as a door handle part?

In the catalogue, broadly yes. Knob and lever trim sit in the same families and share roses, spindles and mounting arrangements on most series. The practical difference is the shape you grip, and on many locks the two are directly interchangeable.

Which Schlage Series Is on Your Door?

The series decides everything downstream, so establish it before looking at any part.

If you have established the lock is mortise, our Schlage L Series mortise lock parts guide covers it at component level. If it is cylindrical, the cylindrical lock parts section is the place to start.

What Is the Difference Between the Inside and Outside Knob Assembly?

They are built for different jobs and they are usually different part numbers.

The outside assembly sits on the secure side. On most functions it carries the cylinder preparation, and whether the knob turns at all depends on the lock function and the state of the lock.

The inside assembly sits on the egress side. It almost always turns freely, because free egress is a requirement, not an option, on the great majority of commercial doors.

Can you fit an outside assembly on the inside?

Usually not, and it is not worth trying. Even where it physically mounts, you can end up with a keyed knob on the escape side of a door, which is the wrong outcome for the building and potentially a code problem.

What Does the Rose Do, and Why Is It Ordered Separately?

The rose is the plate between the knob and the door face. It covers the preparation in the door, carries the fixings and, on many designs, provides the bearing surface the knob turns against.

It gets ordered separately because it fails separately. A rose that has started to spin, worked loose, or been scratched through by years of keys does not mean anything is wrong with the knob or the lock.

Why do roses work loose?

Because they take the side load every time someone leans on the knob or pulls the door closed by it. On a high traffic door that is thousands of cycles a year. Retightening often works for a while, but a rose that keeps loosening usually has worn fixings or a worn seat in the door face.

What Is a Spindle and Does It Come With the Knob?

The spindle is the square or shaped bar that passes through the lock and carries the turning motion from one knob to the mechanism.

Whether it comes with the knob assembly depends on the series. Some assemblies include it, some expect you to reuse the one already in the door, and some list it separately. That is worth checking at the point of order rather than discovering on site.

A spindle that has rounded off produces a knob that turns a few degrees then spins freely. It is a cheap part and a common one on old doors.

Can You Change a Schlage Knob to a Lever?

On most series, yes, and this is the single most common reason these parts get ordered.

Accessibility requirements mean hardware on an accessible route has to be operable with one hand without tight grasping or twisting of the wrist. A round knob cannot meet that, and no adjustment changes it. A lever can.

Because the lock body stays in the door, a knob to lever conversion is a trim order rather than a lock order. The function, the keying and the strike all stay as they are. Our ADA door clearance guide covers the operable parts requirement that drives these conversions.

Does the handing change when you fit a lever?

It can matter where a knob did not. A knob is symmetrical and a lever is not, so a lever has to point the correct way for the door. Confirm the handing from outside the door before ordering.

Are the knobs on a pair of doors always the same part?

Not necessarily. On a pair, the active leaf usually carries a working lock and the inactive leaf often carries dummy trim that operates nothing. Both can look identical from a distance, so measuring and checking behaviour beats assuming.

The same applies to a run of doors along a corridor. They were often fitted at the same time in the same finish and design, but the functions vary by room, and the function is what decides whether the outside knob is keyed, fixed or free.

How Do Knob Designs and Finishes Affect the Part Number?

Both are carried in the number, and both are easy to get wrong because they are the parts of the code people skip.

Design names identify the shape of the knob or lever. Two assemblies that are identical in function and series can have completely different numbers purely because of the design, and they will not look alike on the door.

Finish is a coded suffix. Matching it to the rest of the opening matters more than matching it to a photograph, because photographs of metal finishes are unreliable. Our finish guide lists what the codes mean.

What Fails on a Schlage Knob?

Where the key is involved, check the cylinder before the trim. Our Schlage lock cylinder replacement guide covers the tailpiece question that explains most of those cases.

Can You Replace Just the Knob, or Does the Whole Lock Go?

Just the knob, in almost every case. The exception is when the chassis itself has failed, which shows up as a knob that turns the full travel without retracting the latch even with a sound spindle.

There is one more reason to replace rather than repair, and it is worth being straight about: if a lock has already had two or three trim parts replaced and the door is heavily used, the economics shift. At that point a new lockset of the same function is often the better call.

What about knobs on fire rated doors?

Trim on a fire rated opening has to suit the rating of the assembly, and the door still has to latch positively every time it closes. That rules out dummy trim on an active leaf and makes the latch and strike condition as important as the knob itself.

If a fire door has a knob that is hard to turn, resist the temptation to solve it by loosening anything. A stiff knob on a fire door is usually telling you the latch is binding against a misaligned strike, and that same misalignment is what will stop the door latching when it matters.

How Do You Order the Right Schlage Knob Part?

Our commercial lock function codes guide explains how to read the function, and the Schlage lock parts overview covers the wider range. For the lever specific parts on L Series, see the 09-506 outside lever guide.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the knob design is unfamiliar and there is no stamping to read, send a photograph of the door and the trim through our contact page, or browse Schlage replacement parts and mortise lock parts.

Quick Summary

A door that slams is more than an annoyance. It wakes people, cracks frames, shortens the life of every piece of hardware on the opening, and on a fire door it is a sign something is out of adjustment on a door that has a job to do.

The good news is that the fix is usually a quarter turn of a small screw. This guide explains what is making the noise, which adjustment to touch, how to do it without destroying the closer, and what to do when adjustment is not the answer.

Why Does a Door Slam in the First Place?

A door slams when it arrives at the frame with more energy than the closer is taking out of it. That can happen for four different reasons, and they need different fixes.

The closer is set too fast, so the door is simply moving quickly when it arrives. The closer has failed internally, so it is no longer controlling the swing at all. Something external is pushing the door, usually wind or air pressure in the building. Or there is no closer on the door and the spring hinges are doing all the work.

Before touching anything, open the door to 90 degrees and let it go. Watch the whole arc. Where the door picks up speed tells you which valve to go to.

What should a correctly set door look like?

It should travel steadily from open to nearly closed, then move through the last few degrees firmly enough to latch, without noise. On an accessible opening the standard is that the door takes at least five seconds to travel from 90 degrees down to 12 degrees from the latch, which is slower than most people expect.

Does the Door Actually Have a Closer on It?

It sounds obvious, but it changes the whole answer, and a surprising number of slamming doors have nothing controlling them.

Look at the top of the door on both sides, and at the top of the frame. A surface closer is a visible rectangular body with an arm. A concealed closer is hidden in the frame head or the door itself, with only the arm visible. A floor closer sits in the threshold under the pivot.

If there is nothing at the head and nothing in the floor, the door is either on spring hinges or on nothing at all, and no amount of adjustment exists to be made. Our guide to the four types of commercial door closer covers how to tell which one you have.

Which Closer Adjustment Stops the Slam?

Start with the latch valve. On the overwhelming majority of slamming doors the problem is in the last few degrees, which is exactly what the latch valve governs.

If the whole closing arc is too quick, not just the end, the sweep valve is the one to move. If the door is fine closing but crashes into the wall on the way open, that is backcheck and a different complaint entirely.

How do you find the valves on an unfamiliar closer?

They are small screws, usually on the end of the body opposite the arm, often under a plastic cover. Most are marked, commonly with a letter such as L for latch, S for sweep and B for backcheck, or with numbers keyed to a diagram in the template that came with the unit.

If the markings are worn away, work it out by testing rather than guessing: move one valve a quarter turn, operate the door, and see which part of the swing changed.

How Do You Adjust the Sweep and Latch Valves Safely?

The method matters more than the theory, because the common way to ruin a working closer is to over-adjust it.

Turn the valve clockwise to slow that part of the swing and anticlockwise to speed it up. Move it no more than a quarter to a half turn at a time, then operate the door and watch. Repeat until it is right.

Never wind a valve fully out. The closer is a sealed hydraulic unit under pressure, and a valve backed out past its thread can leave the body and take the oil with it. At that point the closer is finished and the part you need is the cylinder assembly, not a screw.

Our step by step guide to adjusting a commercial door closer goes through the same sequence on specific units.

What If the Door Still Slams After Adjustment?

Then the closer is not controlling the oil any more, and no valve setting will bring it back.

Look for oil. A film on the closer body, a drip mark down the door face, or a damp patch on the cover all mean the unit has lost its seal. A closer that has lost oil cannot meter anything, so the door is effectively swinging on spring power alone.

The other possibility is that the closer is undersized for the door. A unit that is too small for a heavy or wide leaf gets wound up to maximum spring power to make the door latch, and at that setting it has very little control left in reserve. Our closer sizing guide covers matching the size to the door.

Is it the closer or the door?

Disconnect the arm and swing the door by hand. If it binds, catches, or swings back on its own, the problem is the door, the hinges or the frame, and fixing the closer will not help. Hinge wear and a dropped leaf are common and they make every other adjustment unreliable.

Can a Hold Open Arm Stop a Door Slamming?

It can remove the problem on doors where the slamming happens because people are propping the door with whatever is to hand, then letting it go.

A hold open arm keeps the door at a set angle until someone pushes it past the detent. That means no wedge under the door, no bin holding it open, and no sudden release when the prop is kicked away.

One important restriction: a plain hold open arm is not permitted on a fire door. A fire door may only be held open by a device that releases it automatically on alarm.

What Stops a Door Slamming in the Wind?

Wind and stack pressure are not a valve problem. The air is adding energy the closer was never sized to absorb, and winding the valves down further usually just makes the door fail to latch on calm days.

The usual answer is an arm with a cushioned stop built into it. A cush arm slows the door at the end of its opening swing instead of letting it hit a hard stop, and a spring cush version adds a spring that absorbs the shock of a door caught by a gust.

Backcheck is the other half of the answer. Set properly it slows the door before it reaches the fully open position, which is exactly where wind damage happens. Our parallel arm door closer guide covers the arm and shoe options in more detail.

Why Do Fire Doors Slam, and What Can You Change?

Fire doors slam more often than other doors because they are set up to do something other doors are not: latch positively, every single time, without exception.

That means the spring power cannot simply be reduced until the noise stops. If the door stops latching, the opening no longer does its job. The adjustment you have is the latch valve, slowing the approach without removing the force that drives the latch home.

Where that is not enough, the answer is usually mechanical rather than hydraulic: check the latch and strike alignment, check the seals are not adding drag, and check the hinges. A fire door that needs excessive spring power to latch normally has a mechanical problem somewhere. Our guide to adjusting a fire door closer covers the constraints.

What If There Is No Closer At All?

Then the choice is to fit one or to accept the noise, and on most commercial doors fitting one is the right answer.

Adding a closer is not only about noise. It controls the door for everyone who uses it, stops the leaf being blown against the wall, and on a door that needs to be kept shut for fire or security it is the only thing that reliably closes it.

The guide to installing a commercial door closer covers mounting, and the closer selection guide covers choosing the unit.

Which Parts Do You Order to Fix a Slamming Door?

Before ordering, read the series stamping off the closer body. Arms, shoes, covers and cylinder assemblies are all series specific. Browse the door closer parts section, the LCN door closer parts guide, or the 4040XP parts guide if that is the unit on the door.

On accessible openings, remember that the slam fix and the accessibility requirement are linked. Slowing a door is fine, making it too heavy to open is not. Our ADA door clearance guide covers the force and timing limits.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the closer is leaking or the markings on the valves have worn away, contact us with the series stamping and we will confirm which assembly you need, or browse the LCN parts range.

Quick Summary

Somebody calls and says the crash bar on the back door is broken. That sentence is completely clear to everyone in the building and completely useless for ordering a part, because no manufacturer prints the words crash bar on anything.

This guide translates. It covers what a crash bar actually is, the four assemblies inside it, why the door has one in the first place, and how to work out which part has failed before you spend money on the wrong one.

What Is a Crash Bar on a Door?

A crash bar is a horizontal bar across the inside face of a door that releases the latch when you push it. Push anywhere along it, in any direction that moves it towards the door, and the door opens.

The formal name is an exit device. Manufacturers, specifiers and parts catalogues all use that term, along with panic hardware when the device is there to satisfy egress requirements. Crash bar is the name it picked up on site, probably because of what happens when a crowd hits one.

The defining characteristic is that it needs no instruction. There is no knob to turn, no direction to work out and no latch to find. A person moving quickly, in the dark, carrying something, pushes and the door opens.

Why does the name matter when ordering?

Because the catalogue is organised by device series, not by nickname. Once you know the series stamped on the chassis, the parts list narrows from thousands of items to a few dozen. Until then, no amount of describing the bar gets you to a part number.

What Are the Parts of a Crash Bar?

Four assemblies do the work, and they fail independently. Knowing which one you are looking at is most of the diagnosis.

Outside trim is a fifth item but it is not strictly part of the device. It is what gives you a way back in from the outside, and it is ordered separately and matched to the device series.

Which part should you suspect first?

Work from the symptom. A bar that feels loose or rattles points at the rail mounts or the end cap. A bar that moves fully but the door stays shut points at the latch or the connection to it. A door that will not stay shut points at the latch or the strike. A bar that has become stiff points at the center case.

Why Does a Door Need a Crash Bar?

Crash bars are a life safety requirement, not a convenience fitting. The building codes require panic hardware on certain doors so that a crowd can leave without anyone needing to understand the lock.

The triggers are occupancy type and occupant load. Assembly and educational occupancies above a defined occupant load need panic hardware on their egress doors, and rooms containing certain electrical equipment need it regardless of how many people use them. The authority having jurisdiction has the final word on any specific opening.

Our guide to panic hardware on commercial doors sets out the code side in detail, including where the two main model codes differ.

What does the hardware have to do to comply?

Three things, and they are worth stating plainly because they explain the design. The device has to release the latch with a single motion. It has to work with a push, not a pull or a turn. And the force needed has to stay within the limit the code sets, so that a child or someone being pressed from behind can still get out.

What Types of Crash Bar Are There?

The type is decided by where the device latches, which in turn is decided by the door. This is the single most important thing to establish before ordering anything.

If you have established the device is rim type, our rim exit device guide covers it at part level. For the vertical rod versions, see the concealed vertical rod guide.

What Is the Difference Between a Fire Rated and a Standard Crash Bar?

They look nearly identical and they behave differently in one way that matters every day: a fire rated device cannot be dogged.

Dogging is the facility to hold the latch retracted so the door pushes open freely, usually with a hex key or a cylinder. It is how a shop holds a back door operable during trading hours. A fire door has to latch positively every single time it closes, so dogging is not available and the mechanism is not fitted.

Read the label on the edge of the door before ordering. If the opening is fire rated, the device and every part on it has to suit that rating. Our commercial door fire rating guide explains how the labels are read.

What if the device on a fire door has a dogging keyhole?

Then something is wrong with how the opening was specified or the device was replaced at some point with the wrong configuration. It is worth raising, because an inspection will pick it up.

How Do You Identify Which Crash Bar You Have?

Five minutes at the door saves a wrong order. Collect these in sequence.

Door width and handing matter too, because rail lengths and some latch parts are handed. Measure rather than estimate.

What Does It Mean to Dog a Crash Bar?

Dogging holds the push bar depressed and the latch retracted, so the door behaves like a push plate until you undog it. It is used to keep a door freely operable during business hours without propping it with a wedge.

Two mechanisms exist. Hex dogging uses a small hex key in the touchpad end. Cylinder dogging uses a key cylinder, so only keyholders can dog the device. The cylinder version is usual where staff should not be able to leave a door unsecured.

A device that will not dog, or will not release from dogged, almost always has a worn dogging assembly or a rounded hex socket. Both are stocked parts rather than a reason to replace the device.

Can a Crash Bar Have an Alarm on It?

Yes, and it is one of the most common upgrades on a back door that keeps getting used as a smoking exit.

An alarm kit fits to the device and sounds locally when the bar is pushed. It does not lock the door and it does not delay egress, which is the point: the door still opens instantly, but the building knows about it.

Where the requirement goes further than an audible alarm, delayed egress hardware holds the door for a set period before releasing. That is a code controlled function with its own rules, covered in our guide to delayed egress.

Why Would a Door Have a Crash Bar That Does Nothing?

Dummy bars exist and they confuse people regularly. A dummy touch bar has no mechanism behind it. It is fitted to the inactive leaf of a pair so both doors look the same, or used as a pull on a door that does not latch.

If a bar moves but nothing happens and there is no latch visible anywhere on that leaf, you are probably looking at dummy trim rather than a fault.

What Goes Wrong With Crash Bars in Service?

These are the complaints that come to us most often, and what they usually turn out to be.

How Do You Order the Right Crash Bar Parts?

Order by assembly, not by device. The device series and the configuration narrow the list, then the symptom tells you which assembly to buy.

Parts do not cross between series, and they rarely cross between the standard and fire rated versions of the same series. A part that looks identical in a photograph can have a different internal profile.

Start from the exit device parts section, or the 98 and 99 Series parts guide if that is what is on the door. For the naming question that brought you here, our comparison of exit devices and panic bars covers where the terms came from.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If all you have is a photograph and the words crash bar, that is enough to start. Send it through our contact page with the door type and we will identify the series, or browse Von Duprin parts if you already have a number.

Quick Summary

Concealed vertical rod devices look like the obvious choice right up until the first service call. They give you a clean pair of doors with nothing running up the face, and then eighteen months later the top latch stops engaging and nobody can work out how to get at the rod.

This guide explains what the device is actually doing, where it is the right answer, where it is not, and how to work through the latching problems that make up most of the service work on these openings.

What Is a Concealed Vertical Rod Exit Device?

A concealed vertical rod exit device, usually shortened to CVR, is an exit device that latches the door at two points: a latch at the top that engages a strike in the frame head, and a latch at the bottom that engages a strike in the threshold or floor.

The two latches are driven by rods that run from the device up and down inside the door. Pushing the touchpad pulls both rods at once, retracting both latches, and the door is free.

The word that does the work is concealed. On a surface vertical rod device, the same mechanism exists but the rods are visible on the face of the door, held in place by brackets. On a CVR device the rods live inside the door and nothing shows.

How Does a CVR Device Latch the Door?

Three parts have to agree for the door to latch: the latch itself, the rod that drives it, and the strike it engages. If any one of those three is out of position the door will not stay shut, and all three are adjustable.

The top latch engages a strike mounted in the frame head. The bottom latch engages a strike set into the threshold, or in some configurations drops into a floor socket.

Why two latching points changes the behaviour

A rim device has one latch. If it engages, the door is shut. A CVR device has two, and the door can appear shut while only one of them is doing anything.

That is the source of most CVR confusion. Somebody pulls the door and it holds, so the device is assumed to be working, when in fact only the top latch is engaging and the bottom latch has been missing its strike for months.

CVR vs SVR vs Rim vs Mortise: Which Device Type Is on Your Door?

Identification takes about ten seconds once you know what to look at, and it has to be settled before any part is ordered because the latching components differ completely between configurations.

Pairs of doors are the usual home for vertical rod devices, because without a mullion between the leaves there is nothing in the middle for a rim latch to engage. Our mullion guide covers the alternative approach to the same problem.

If you have established that the device is rim rather than vertical rod, our rim exit device guide is the better starting point.

Why Would You Specify Concealed Vertical Rod?

Three reasons come up repeatedly, and they are all good ones.

Appearance is the first. On a glazed entrance or a prestigious opening, rods running up and down the face of the leaf are the visual element nobody wants. Concealing them leaves a clean door.

Protection is the second. Exposed rods get knocked by trolleys, caught by luggage and bent by people pushing on them. Rods inside the door cannot be reached, so they cannot be damaged by ordinary traffic.

Security is the third. There is nothing on the surface to interfere with, which matters on doors that are accessible to the public outside staffed hours.

What Are the Drawbacks of CVR?

The drawbacks are all versions of the same thing: the parts you most need to reach are the ones you cannot see.

That last point is the one that catches specifiers. Surface rod conversion kits exist precisely because moving in the other direction, towards exposed rods, is something you can do on site.

What Does LBR Mean and When Is It Used?

LBR stands for less bottom rod. The device is supplied without the bottom rod and bottom latch, so it latches only at the head.

The reason is the environment at the sill. A bottom latch sits where mop water, grit and floor dirt accumulate, and on a busy opening it is the component that stops working first. Removing it removes the problem.

LBR is common on fire rated openings, where the device still has to latch positively, but the designers would rather put all of that responsibility on the top latch than risk a bottom latch that is fouled with dirt. Where a bottom rod is removed, the configuration has to be the one the manufacturer intends, not simply the original device with parts left off.

Identifying an LBR device

Look at the bottom of the door. If there is no latch emerging from the bottom edge and no strike in the threshold, the device is either LBR or the bottom components have been removed by someone. Those are very different situations, and the door schedule is the way to tell them apart.

What Fails on a Concealed Vertical Rod Device?

The failures are consistent across manufacturers because the mechanism is the same shape everywhere.

How Do You Adjust Vertical Rods?

Adjustment is about travel, not about tension. The rod has to retract the latch far enough to clear the strike when the touchpad is pressed, and it has to let the latch return fully when the touchpad is released.

Work with the door open first so you can see what the latches are doing without the frame in the way. Press the touchpad, confirm that both latches retract fully, then release and confirm both return fully. A latch that returns sluggishly will not engage a strike reliably.

Then close the door slowly and watch where each latch meets its strike. If a latch is arriving high, low or off to one side, the strike is the thing to move, not the rod.

Why the door closer gets blamed and sometimes deserves it

A CVR device needs a positive push at the very end of the swing to drive both latches home. If the closer has lost its latch speed, the door drifts into the frame and the latches do not engage.

That presents as a device fault and is not one. Before stripping the device, check the closer. Our guide to adjusting a commercial door closer covers the latch valve, which is the adjustment that matters here.

What Changes on a Fire Rated CVR Device?

Fire rated configurations behave differently in two ways that matter every day.

Dogging is not available. A fire exit device may not be held in the retracted position, because the door has to latch every time it closes. If a device on a fire door has a dogging keyhole, something is wrong with how the opening was specified.

Latching has to be positive. The door has to actively latch, not merely come to rest against the frame, which is why rod adjustment on a fire rated CVR device is a life safety matter rather than a convenience one.

Our commercial door fire rating guide and the NFPA 80 inspection guide cover what an inspection is looking for on these openings.

Which Parts Do You Order and What Do You Need to Know First?

Four pieces of information settle a CVR parts order, and three of them have to be read off the door rather than guessed.

For the model level breakdowns, our 9947 CVR parts guide and 9847 CVR parts guide list the components by assembly, and the exit device parts section covers the wider range.

If you are still deciding between device types rather than repairing one, our exit device and panic bar comparison and the Von Duprin series comparison cover the choice, and panic hardware on commercial doors covers where the code requires a device at all.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the device stamping is hidden under the cover and you would rather not pull the door apart to find it, contact us with a photograph of the device and the door, and we will narrow it down before you order.

Quick Summary

Parallel arm is the mounting most people have seen the most and named the least. It is the flat looking arm tucked up against the door face in corridors, schools and hospitals, chosen because nothing sticks out into the space where people walk.

This guide covers how parallel arm mounting differs from the alternatives, why it changes the spring size you need, what the shoe is doing, and which parts to order when something on the arm side fails.

What Is a Parallel Arm Door Closer?

A parallel arm door closer is a surface closer mounted on the push side of the door, with the closer body fixed to the door leaf and the arm running back parallel to the face of the door to a shoe mounted on the underside of the frame head.

The name describes the arm, not the closer. When the door is closed, the arm lies flat along the door rather than standing out at an angle, which is the whole point of the arrangement.

Almost every common surface closer can be mounted in all three positions. What changes is the arm, the shoe and sometimes a bracket or plate, so converting a door from one mounting to another rarely means a new closer.

Parallel Arm, Regular Arm or Top Jamb: How Do the Three Mountings Differ?

The differences come down to which side of the door the closer lives on and where the load is transferred.

Regular arm puts the closer on the pull side of the door, with the arm reaching up to the soffit of the frame. It is the most mechanically efficient arrangement, and it is the one where the arm is most exposed, because it projects out from the door.

Top jamb puts the closer on the frame rather than the door, on the push side. It is used where the door leaf cannot take the closer body, for example on a narrow stile aluminium door, or where the door is a pair of glazed leaves.

Parallel arm puts the closer on the door on the push side, with the arm folded back. It gives the cleanest result in a corridor and it protects the arm, at the cost of efficiency.

Why Does Parallel Arm Mounting Need More Spring Power?

This is the part that surprises people. A door that works perfectly on regular arm mounting can feel weak and fail to latch when the same closer is moved to parallel arm.

The reason is leverage. In parallel arm mounting the arm works at a less favourable angle through most of the swing, so less of the closer spring energy reaches the door as closing force. The closer has not changed. The geometry has.

In practical terms that means you plan for a higher spring setting on a parallel arm installation than you would on the same door with regular arm mounting, and you check that the door still latches under the conditions it actually sees.

That third row is the tension to be aware of. Accessible openings cap the force needed to open an interior hinged door, and parallel arm mounting pushes the spring setting the other way. Where both requirements bite, the answer is usually a correctly sized closer rather than a compromise, and sometimes a power operator. Our closer sizing guide covers how the sizes map to door width and weight.

When Should You Choose Parallel Arm?

Four situations point strongly at parallel arm mounting.

The door opens into a circulation route. A projecting arm in a corridor is both a snag hazard and something people walk into, so folding it flat against the door removes the problem.

The opening sees abuse. Schools, hospitals, back of house areas and anywhere trolleys pass through all shorten the life of an exposed arm. A parallel arm sits out of the way.

The appearance matters. On a visible entrance the flat profile reads as tidier than an arm standing out at an angle.

A stop is needed and there is no room for a separate overhead stop. Parallel arm shoes are available with stop functions built in, which solves two problems with one part.

What Is the Shoe and Why Does It Matter?

The shoe is the bracket that fixes to the underside of the frame head and receives the forearm of the closer arm. On a parallel arm installation it is the part that makes the mounting what it is.

Two things follow from that. First, the shoe is a separate part, so a damaged shoe does not mean a new closer or even a new arm. Second, shoes are not universal, so the closer series has to be identified before ordering.

The shoe is also what carries the stop function on the variants that have one. The arm pushes against a built in stop inside the shoe at the end of the opening swing, so the shoe is doing structural work as well as locating the arm.

What Are Cush-N-Stop and Stop Arms?

These are parallel arm variants with a stop built into the shoe, so the door is prevented from opening past a set angle without a separate overhead stop or a floor stop.

A plain stop arm provides a hard stop. A cush arm cushions the end of the swing rather than stopping it abruptly. A spring cush arm adds a spring to absorb the energy of a door that is thrown open, which is the version specified where abuse is expected.

One caution. A stop built into the arm transfers the force of a door being thrown open into the closer and into its fixings. On a genuinely abusive opening a separate overhead stop alongside a plain arm is often the longer lasting arrangement.

What Is an Extra Duty Arm and When Do You Need One?

An extra duty arm is a heavier parallel arm built for openings where a standard arm will not survive. It is the answer to doors that get kicked, propped, pulled and generally mistreated.

The clue that you need one is the failure history. If the same opening has had arms replaced more than once, the fix is not another standard arm, it is a heavier one, and probably a look at whether the door has a stop at all.

Extra duty arms and stop arm variants are often specified together on the worst openings, because an abused door usually has both an arm problem and a swing control problem.

Do You Need a Mounting Plate or Bracket?

Often, yes, and it is the part most frequently left off an order.

A parallel arm installation sometimes needs a mounting plate to give the closer body something to fix to, particularly where the door construction will not take the fixings directly, or where an existing fixing pattern does not match the new closer.

Drop plates and brackets solve the related problem of frames with a narrow soffit, or doors with glazing stops in the way. These are stocked separately and are series specific like the shoe.

The practical rule when replacing a closer on an existing door is to confirm what is currently fixed to the door and frame before ordering, because the old plate may not suit the new closer and discovering that on site costs a return visit.

What Goes Wrong With Parallel Arm Installations?

The useful habit is to separate arm side problems from closer body problems before ordering anything. An arm, a shoe and a plate are inexpensive parts to change. Our LCN door closer parts guide breaks the assemblies down, and the guide to the four main types of commercial door closer covers where surface closers sit overall.

What Do You Need to Confirm Before Ordering an Arm?

If the closer is being replaced rather than repaired, confirm the size as well. Our LCN closer selection guide covers choosing the unit, installing a commercial door closer covers fitting it, and the door closer parts section covers the components.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

To match an arm to the closer you already have, browse LCN parts or the door closer parts section, or contact us with the series stamping and we will confirm the arm, shoe and plate together.

Quick Summary

The 996L is one of those parts that is easy to order wrongly. The lever looks the same across the range, the escutcheon looks the same, and the difference between two part numbers can be a single letter that changes how the door behaves for everyone who uses it.

This guide sets out what each variant does, which device the trim has to match, and the four pieces of information that settle the order, so you can replace trim without changing the way the opening works.

What Is the Von Duprin 996L and What Does It Do?

The 996L is outside trim for an exit device. An exit device on its own handles one direction only: push the bar from the inside and the door opens. Trim is what gives you a controlled way back in from the outside.

It consists of an escutcheon plate, a lever and, in most functions, a cylinder that decides whether the lever is live. The trim does not latch the door itself. It reaches through to the device and operates the device latch.

That relationship is the thing to hold on to. If the lever turns freely and the door does not open, the problem is as likely to be in the device as in the trim, and swapping the trim will not fix it.

Which Exit Devices Does the 996L Trim Fit?

Trim is matched to the device family, not just to the door. The 996 range is the trim family used with Von Duprin exit devices, and the specific device series decides which variant of the trim is correct.

Before ordering, identify the device underneath. The series stamping, the chassis shape and the device configuration all feed into the trim choice, and a trim that physically mounts is not necessarily a trim that operates the latch correctly.

Our Von Duprin 98 and 99 Series parts guide and the Von Duprin series guide cover how to read the device before you look at trim at all.

What Do the 996L Suffixes Mean?

The base number tells you the family and the lever. Everything after it tells you the behaviour.

This is the single most common ordering mistake on trim. A 996L and a 996L-NL look almost identical on the door and behave completely differently for the person trying to get in, so a like for like replacement has to carry the suffix across.

Reading an existing trim

The suffix is not always stamped where you can see it. If the trim is already fitted and unmarked, work it out from behaviour instead: try the lever with the door unlocked, then with it locked, and see whether the key retracts the latch or merely changes what the lever does.

Why the suffix is a safety decision, not a preference

Changing the suffix changes who can get through the door. Replacing a night latch trim with a standard lever trim turns a key controlled service entrance into a door anyone can open by hand. Replacing a standard trim with dummy trim locks out people who are supposed to have access.

Because the hardware mounts identically, neither mistake announces itself during installation. It shows up later, as a security incident or as a complaint that a door no longer works. Confirm the function before the old trim comes off the door, not after.

How Does the 996L-NL Night Latch Version Behave?

On a night latch trim the lever is not a latch operator. It is a pull. The key is what retracts the device latch, and it does so only while it is turned.

That makes it the standard choice on doors where nobody should be able to walk in by turning a handle, but authorised staff need key access. Service entrances, delivery doors and back of house openings are the usual homes for it.

The failure mode people report is a night latch that stops retracting the latch. That usually points to the cylinder, the tailpiece length or the device, in that order, rather than to the trim body. Our 880 night latch trim guide covers the same function on a different trim family.

When Would You Use 996L-BE or 996L-DT?

These two look similar on paper and do different jobs.

The 996L-BE is blank escutcheon trim. There is no cylinder preparation, so there is no outside key access at all. It is used where the opening is controlled some other way, or where an outside key would create a security problem rather than solve one.

The 996L-DT is dummy trim. The lever does not operate anything. It exists to give a hand hold and to make a pair of doors look consistent, which is why it so often ends up on the inactive leaf.

What Is Key Capture Trim and Who Needs It?

Key capture trim holds the key while the trim is in the unlocked state. The key cannot be withdrawn until the trim is returned to locked, which means the person who unlocked the door cannot walk away and leave it unlocked without noticing.

Schools, shared buildings and any site where several people hold the same key are the places this earns its keep. It converts a procedural rule into a physical one.

If you already have standard 996L trim and want this behaviour, there is a stocked conversion kit rather than a requirement to buy complete new trim. That keeps the escutcheon, lever and finish you already have on the door.

What Is the M996 Motorized Trim and Can You Convert to It?

M996 is the motorized version of the same trim family. Instead of a cylinder deciding whether the lever is live, an electrical signal does, which is what lets the outside of an exit device join an access control system.

It is used where a card reader, a keypad or a scheduled unlock has to control entry while egress stays mechanical. The device still opens from the inside with a push, whatever the trim is doing.

Conversion is a stocked route. There is a kit specifically for taking 996 R, V and C function trim to M996 motorized, so an existing mechanical opening can be brought onto access control without replacing the device.

For how that fits into the wider system, see our access control hardware integration guide and the QEL conversion kit parts guide, which covers the equivalent change on the device side.

996L Lever or 996K Knob: Which Is Fitted and Which Should Be?

The same trim family exists with a knob, designated 996K. Mechanically the two do the same job. For accessibility they do not. Our Schlage door knob parts guide covers knob assemblies, roses and what to order.

Hardware on an accessible route has to be operable with one hand without tight grasping or twisting of the wrist, and a knob cannot be turned without doing both. That is why a 996K on a main entrance tends to become a 996L after an accessibility review.

If the trim is being changed for that reason, the finish and the device series stay the same, so only the trim part number changes. The device, the cylinder and the strike can all stay where they are.

What Do You Need to Confirm Before Ordering 996L Trim?

Four pieces of information. Collect them at the door and the order becomes straightforward.

Cylinders are the fifth consideration, and they are usually ordered separately. Confirm whether the trim you are buying includes cylinder preparation, whether you are reusing an existing cylinder, and whether the keyway matches the rest of the site. Our mortise cylinder and rim cylinder guide covers which cylinder type belongs with which device.

What Fails on 996L Trim?

Trim failures are mechanical and predictable. The lever is the part that absorbs daily use, so it is the part that wears.

Start every one of these at the device rather than at the trim. The Von Duprin parts guide and the exit device parts section cover the components the trim is reaching through to.

Trim that was never right in the first place

Not every trim problem is wear. A proportion of the trim we are asked about was ordered as a visual match rather than a functional one, usually during a refurbishment where somebody matched the finish and the lever shape and did not check the suffix.

The clue is that the door has behaved the same way since the work was done. Wear comes on gradually, a wrong part is wrong from day one. If staff say the door has never worked properly since it was changed, check the function before you check for wear.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

To see the trim variants side by side, start at the 996 trim range or browse Von Duprin parts. If you are not sure which function is on the door, contact us and describe how the lever and key behave.

Quick Summary

Any time an electrified lock, a latch retraction device or a monitoring switch goes on a door, somebody has to answer an awkward question: how does the wire get from a frame that never moves into a leaf that swings a few hundred times a day without breaking?

The electric hinge is one answer, and often the neatest one. This guide covers how it works, when it is the right route, how to size it, and why most problems with electrified doors turn out to live in this part of the system rather than in the lock.

What Is an Electric Hinge and What Problem Does It Solve?

An electric hinge is a door hinge with conductors built into it. Externally it looks like a normal butt hinge. Internally, a set of small wires passes through the knuckle, so the two leaves of the hinge are electrically connected as well as mechanically connected.

The problem it solves is flex. A cable stretched between a frame and a door would be bent through the same arc at the same point thousands of times, and copper that is flexed repeatedly at a single point eventually breaks. Routing the conductors through the pivot axis means they twist rather than bend sharply.

The second thing it solves is appearance and tamper resistance. There is nothing on the surface to cut, catch or paint around, which matters on public facing entrances and on doors where a visible loop would invite interference.

How Does an Electric Hinge Actually Carry Power?

The conductors leave the hinge through a small opening at the back of each leaf. One set goes into the frame, where it joins the wiring from the power supply and the access control panel. The other set goes into the door, where it runs through a raceway drilled inside the leaf to whatever device needs it.

Inside the knuckle the wires are arranged so that opening the door twists them gently along their own axis rather than folding them. That is the whole trick, and it is why a hinge route lasts where a casually routed cable does not.

The hinge is still a hinge

It is easy to treat an electric hinge as an electrical component that happens to be hinge shaped. It is not. It still carries the weight of the door, so it has to suit the door size, weight and frequency of use exactly as a plain hinge would.

If the opening has three hinges and one is swapped for an electric version, the other two have to be in good condition. A sagging door puts a shearing load through the knuckle, and that is precisely where the conductors are.

Electric Hinge, Power Transfer or Armored Loop: Which Route Should You Use?

All three move power from frame to door. They differ in how much current they will carry, how much preparation they need and how visible they are.

In practice the deciding question is what is at the far end. Monitoring switches and small solenoids are comfortable on a hinge. Motor driven devices usually push you towards a power transfer. Our electric power transfer guide covers that side in detail.

How Many Conductors Do You Need?

Count the devices in the door leaf first, then count the wires each one needs, then add spares. Counting devices and stopping there is how installers end up one pair short on the day.

Two rules keep people out of trouble. Always specify spare conductors, because adding a monitoring function later is cheap if the wires are there and expensive if they are not. And always check the inrush, not just the holding current, on anything with a motor in it.

What Hardware on the Door Actually Needs Power?

It helps to be precise about which side of the opening each device sits on, because only the devices in the moving leaf need the transfer route at all.

Electric strikes do not. A strike lives in the frame, so it is wired directly and needs no transfer. That single fact is why a strike is often chosen over an electrified lock when retrofitting an existing door.

Electromagnetic locks usually do not either, because the magnet mounts to the frame or header and only the armature plate goes on the door. Our electromagnetic lock parts guide covers the exceptions.

What does need the route is anything electrified inside the leaf: electrified lock bodies, electrified exit device trim, latch retraction devices, request to exit switches built into the device, and latch monitoring contacts. If you are weighing a door mounted option against a frame mounted one, our electrified mortise lock and electric strike comparison sets out the trade.

What Preparation Does the Door and Frame Need?

Three pieces of preparation have to line up, and all three have to be decided before anything is ordered.

The hinge mortise has to suit the hinge. Size, backset and screw pattern all follow the hinge model, and an electric hinge is not always dimensionally identical to the plain hinge it replaces.

The frame needs a route from the hinge pocket back to the point where the field wiring arrives. On a new frame this is designed in. On an existing frame it is often the hardest part of the job.

The door needs a raceway, a drilled path from the hinge pocket to the device location inside the leaf. On a hollow metal door this is factory work rather than site work, which is why electrified hardware is so much easier to specify at order time than to retrofit.

Weatherised and exposed openings

Exterior openings add a requirement the drawings often miss. Where the route is exposed, the cable itself needs protection against weather and against physical damage.

Does an Electric Hinge Work on a Fire Rated Door?

Fire rated openings can carry electrified hardware, but everything on the opening has to be compatible with the rating, and the hinge is part of the opening.

The constraints that matter are the ones that always matter on a fire door. The door has to self close and positively latch every time, and nothing fitted to the opening may prevent that. Hardware has to suit the rating of the assembly.

Practically, that means the fire rating of the assembly has to be checked against every component, the hinge included, before parts are chosen. Our commercial door fire rating guide covers how the labelling works and what it restricts.

Why Do Electric Hinges Fail, and What Does Failure Look Like?

Failures are almost always mechanical in origin even though they present electrically. The conductors are the thinnest part of the system and they live inside the part that moves.

That last row deserves attention. A route that reads perfectly on a continuity test can still fail under load, because a thin conductor drops voltage once current flows. Always measure at the device while it is working.

How Do You Troubleshoot a Dead Electrified Door?

Work from the power supply towards the device, and prove each stage before moving on.

Start at the supply and confirm the output under load, not at rest. Then confirm the signal is arriving at the frame side of the transfer route. Then check continuity across the transfer with the door closed, and again with the door open, because a fatigued conductor often reads fine in one position and open in the other.

Only when the transfer route is proven should the device itself be suspected. Our commercial door hardware troubleshooting guide covers the rest of the sequence, and the access control integration guide covers how the panel side should behave.

What Should You Confirm Before Ordering?

Get those six settled and the order is simple. Skip one and the usual outcome is a second visit, because transfer routes are not something you can change your mind about once the door has been cut.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

To compare transfer options side by side, browse Detex parts and Von Duprin parts, or contact us with the device list and conductor count and we will confirm the route before you order.

Quick Summary

Most people meet ADA door clearance as a line on an inspection report rather than as a design decision. Somebody measures an opening, writes down a number that is short by an inch, and the building owner is left guessing whether that means a new door frame or a different part.

In practice the answer is usually a part. This guide walks through each clearance requirement in turn, explains what is actually being measured, and shows which piece of door hardware controls it, so you can work out whether the opening needs a carpenter or a box from the shelf.

What Does ADA Door Clearance Actually Mean?

ADA door clearance is shorthand for a group of requirements in the 2010 ADA Standards for Accessible Design that together make a doorway usable by someone with limited mobility, limited reach or limited grip strength.

The requirements fall into two families. The first is about space: how wide the opening is and how much floor there is to maneuver on either side. The second is about effort: how hard the door is to pull, how fast it comes back, and whether the handle can be worked with a closed fist.

The split matters because the two families have very different remedies. Space problems are building problems. Effort problems are hardware problems, and hardware problems are the ones you can usually solve without touching the structure.

Which doors have to comply?

Accessible routes are the trigger. Doors on an accessible route into and through a building have to meet these requirements, which in most commercial buildings means the main entrance, corridor doors, restroom doors and the doors to any space the public or employees are expected to reach.

Doors that are not on an accessible route, such as a door to a space entered only for maintenance, are treated differently. Local code and the building official have the final word, so confirm the scope before you start replacing parts.

How Much Clear Width Does an Accessible Door Need?

The standard calls for a minimum of 32 inches of clear width. The measurement is taken with the door open 90 degrees, from the face of the door to the opposite stop. It is not the width of the frame and it is not the width of the leaf.

That distinction catches people out. A 36 inch leaf does not give you a 36 inch opening, because the thickness of the door and the depth of the stop both eat into the gap. A 32 inch leaf will not pass at all.

Hardware can eat into it too. Door mounted projections between 34 and 80 inches above the floor are limited to 4 inches of projection into the opening, which is why surface mounted exit device chassis and bulky pull trim get looked at closely on narrow leaves.

Doors in series

Vestibules have their own rule. Where two doors are in series, there has to be at least 48 inches between them, measured clear of the swing of any door that opens into the space. A tight vestibule with two inward swinging doors is one of the most common failures on older buildings.

What Maneuvering Clearance Is Required on Each Side of the Door?

Clear width gets a person through the gap. Maneuvering clearance gives them the floor space to position a wheelchair, reach the handle and pull the door without being pushed backwards by it.

The required space changes with the direction of approach and with which side of the door you are on. The pull side always needs more room than the push side, because the user has to retreat as the door comes towards them.

That bottom row is the one that surprises facilities teams. Adding a door closer to a door that already has a latch changes the maneuvering clearance requirement on the push side. A closer is not a neutral addition to an opening.

Hinge side and latch side approaches have their own figures, and they are more generous in depth because the user is coming at the door from an angle. If an opening fails on approach geometry and the walls cannot move, a power operator is usually the way out.

How Much Force Can It Take to Open the Door?

Interior hinged doors are limited to 5 pounds of opening force. Sliding and folding doors carry the same 5 pound limit. The figure applies to the effort needed to get the door moving and to keep it swinging, not to the effort needed to release a latch.

Exterior doors are the exception people misquote. The ADA Standards do not set a maximum opening force for exterior hinged doors, which is why wind load and stack pressure are handled through local code and through the choice of closer rather than through a single national number.

Fire doors are the other exception. A fire rated door has to latch positively every time, which takes spring power, so the standard allows the minimum opening force permitted by the authority having jurisdiction rather than a flat 5 pounds.

Why the closer is almost always the cause

A door closer works by compressing a spring as the door opens. The stronger the spring setting, the harder the pull. Facilities teams raise the spring power to make a door latch reliably, then fail the opening force test without realising the two are connected.

The honest fix is rarely to weaken the spring until the door stops latching. It is to reduce the resistance the spring is fighting: free up a binding hinge, correct a dragging sweep, fix a strike that the latch is scraping into, and only then reset the spring.

How Slowly Does the Door Have to Close?

Closing speed is specified as a minimum time, which trips people up because every other door requirement is a maximum. The door has to take at least 5 seconds to travel from 90 degrees open down to 12 degrees from the latch.

Where spring hinges are used instead of a closer, the equivalent requirement is that the door takes at least 1.5 seconds to swing from 70 degrees to the closed position.

On a conventional closer this is the sweep valve, the adjustment that governs the main part of the swing. Latch speed, the short burst at the end, is a separate valve and is not what the 5 second measurement is testing.

If you are working through these valves on a specific unit, our guide to adjusting a commercial door closer walks through the order to do them in, and the closer sizing guide covers choosing the right size in the first place.

What Height Does the Door Hardware Have to Be?

Operable hardware has to sit between 34 and 48 inches above the finished floor. That band covers levers, panic bar touchpads, thumbturns and anything else a user has to work to get through the door.

Most commercial hardware lands inside the band by default, because standard lock heights put a lever at around 38 to 40 inches. The parts that drift outside it are additions: a surface bolt near the top of the door, a secondary deadbolt fitted high, or a thumbturn mounted above the main lock.

On a pair of doors, check the inactive leaf as well. Flush bolts at the head of the inactive leaf are not operable parts in the accessibility sense, but any hardware a user is expected to work to pass through the opening is.

Which Types of Door Hardware Meet the Operable Parts Rule?

The rule is written in terms of what the user must not have to do. Hardware must be operable with one hand and must not require tight grasping, tight pinching or twisting of the wrist. Operating force is capped at 5 pounds.

That wording is what rules out the round knob. A knob cannot be turned without grasping and twisting, and no amount of adjustment changes that. It also rules out small thumbturns that need a pinch grip, and tight recessed pulls.

Levers that have stopped behaving

A compliant lever that has worn is a quiet failure. Once the return spring weakens the lever droops, and a drooping lever is both a snag hazard and a sign the latch is no longer being fully retracted. Spring cages and lever kits are stocked as individual parts for exactly this reason.

When Does a Power Operator Become the Only Practical Answer?

Three situations push an opening towards a powered solution. The maneuvering clearance is not there and the walls cannot move. The door is a fire door that has to latch, so the spring power cannot come down. Or the door is an exterior door fighting wind and stack pressure.

Low energy operators are the type used on accessible entrances. They open the door slowly, under limited force, and only when a person deliberately activates them by pressing a plate or waving at a sensor. They are covered by ANSI/BHMA A156.19, which sets the opening and closing timings.

The operator is only half the decision. The activation device is a separate choice, and it has its own reach and height requirements because a user has to be able to work it from a clear floor space that does not sit in the path of the opening door.

For the whole powered opening, including sensors and control boxes, see our commercial door operators guide and the door operator parts guide.

What About Thresholds and the Bottom of the Door?

Thresholds at doorways are limited to half an inch in height. Anything above a quarter inch has to be beveled, at a slope no steeper than one in two, so a wheel can ride up rather than stop against a square edge.

The push side of the door has its own rule. The bottom 10 inches has to present a smooth surface across the full width, so a footrest can push the door open without catching. Projecting kick plate edges and applied mouldings in that zone are what fail this one.

Both of these are easy to break during a repair. A new sweep that stands proud, or a kick plate fitted with raised fixings, can put a previously compliant door outside the rule without anyone noticing.

Which Parts Do You Actually Change to Bring an Opening Into Compliance?

Working from the most common finding to the least, the fix list is short and almost all of it is parts rather than construction.

Before ordering anything, confirm what is already on the door. The closer body, the arm and the mounting plate are separate line items, and an arm change alone sometimes solves a force problem that looks like it needs a new closer. Our door closer parts section and the guide to the four types of commercial door closer cover how those pieces fit together.

Where the opening is also fire rated, check the two requirement sets together rather than one after the other. Our commercial door fire rating guide and the ANSI and BHMA standards guide explain where the grading and labelling requirements sit alongside accessibility.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If you have a measurement that is failing and you know the hardware on the door, start with the parts by product type index, or contact us with the model number and we will confirm the part before you order.

Quick Summary

Falcon hardware tends to turn up on a job without any paperwork. Somebody inherits a building, a lever snaps or a device stops dogging, and the only clue to what is installed is a stamping on the chassis and a shape that looks familiar.

This guide is the orientation layer. It covers which Falcon families exist, how to tell them apart on the door, how the service part numbering behaves, and which of our deeper part guides to go to once you know what you are holding.

What Is Falcon Door Hardware and Where Does It Sit?

Falcon is a commercial door hardware line covering exit devices, cylindrical locks, mortise locks and the cylinders and trim that serve them. It is specified where a building needs dependable, serviceable hardware without the weight and cost of the heaviest institutional ranges.

The practical consequence for a facilities team is that Falcon openings are repairable. The ranges were designed around replaceable sub assemblies rather than sealed units, so a failure usually resolves to one part rather than to a new lock.

That is also why identification matters more than it does on some ranges. The same lever can appear across several chassis, and the same looking exit device can be a 24 or a 25 depending on the stile it was built for.

Which Falcon Product Families Will You Find on a Commercial Door?

Four families account for nearly everything in service. Knowing which one you are looking at narrows the part search from thousands of numbers to a few dozen.

Exit devices

The 19 Series is the lighter of the three exit device ranges. The 24 Series is the heavy duty narrow stile device, built for aluminium and glass openings where there is very little stile to work with. The 25 Series is the heavy duty wide stile device used on hollow metal and wood doors.

Each of those series then carries configurations: rim, surface vertical rod, concealed vertical rod and mortise. The configuration decides which latching parts exist, so it has to be settled before any part is ordered. Our Falcon 19, 24 and 25 Series parts guide works through each one.

Cylindrical locks

The T Series is the Grade 1 cylindrical lockset. It is the family you meet on classroom and office doors, and the one whose spring cage becomes a talking point once levers start to sag. The Falcon T Series parts guide covers the function codes and chassis numbers.

Mortise locks

The M Series is the mortise family. Mortise locks carry their functions inside a single case set into the edge of the door, and the function is changed with cams and internal parts rather than by swapping the whole lock.

Cylinders, trim and keying parts

Cylinders sit across all three families. Deadbolt cylinders, keyed in lever kits and the tailpieces that connect a cylinder to a chassis are ordered separately from the locks themselves.

How Do You Tell Which Falcon Exit Device You Have?

Start with the door, not the device. The stile is the single most useful clue, because the narrow stile and wide stile ranges were built for different openings and rarely appear on the wrong one.

Next look at the rods. No rods at all means a rim device latching into a strike on the frame. Visible rods running up and down the face of the door mean surface vertical rod. No visible rods but latches top and bottom means concealed vertical rod, with the rods running inside the door.

Finally check the dogging. A hex dogging keyhole in the touchpad end tells you the device can be held in the retracted position, which in turn tells you it is not a fire rated configuration, because fire devices are not allowed to be dogged down.

What Is the Falcon T Series and How Is It Serviced?

The T Series is a cylindrical lockset, meaning the working parts sit in a chassis that passes through a bored hole in the door face, with the latch running into the edge.

Service on a cylindrical lock is mostly about three sub assemblies. The chassis carries the function. The spring cage returns the lever. The latch and strike decide whether the door actually stays shut.

The symptoms and what they point to

A lever that droops points at the spring cage. A lever that turns but does not retract the latch points at the chassis or the lever connection. A door that will not stay shut, with the lever behaving normally, points at the latch or at strike alignment rather than at the lock.

That last one is worth separating out, because a misaligned strike gets blamed on the lock more often than anything else. Our cylindrical lock parts guide covers how the pieces relate.

What Does the Falcon M Series Cover?

The M Series is the mortise range. A mortise lock case is let into a pocket cut in the edge of the door, which gives it room for more internal mechanism than a cylindrical lock has.

That extra room is why mortise locks carry the more complex functions, and why the cam becomes an ordering decision. Cams translate the turn of the cylinder into movement inside the case, and different functions take different cams.

If you are working on the mortise case itself rather than the cylinder side, the mortise lock parts guide covers the internal components, and commercial lock function codes explains how the function designations are read.

How Do Falcon Service Part Numbers Work?

Falcon service parts do not all share one numbering scheme. They carry prefixes that group parts by the family they serve, and recognising the prefix tells you which family you are in before you read the rest of the number.

The lesson is simple. A partial number is not enough. The suffix after the prefix usually carries the finish, the pin count or the specific variant, and two parts that differ only in the last three digits can be completely different items.

Which Falcon Parts Fail First?

Across the families the failures cluster into a short list, and most of them are wear items rather than defects.

The pattern is that a Falcon problem is usually a sub assembly problem. Before ordering a complete lock or device, confirm which of these the symptom actually matches.

Can You Mix Falcon Parts With Other Hardware on the Same Door?

Within the cylinder and keying world, yes, and the catalogue reflects it. There are tailpieces and keyed in lever kits made specifically so a Falcon cylinder can serve a lever or chassis from another range in the same family of brands.

That is a deliberate convenience rather than an accident, and it is why you will find parts described as a Falcon tailpiece or a keyed in lever for a Falcon cylinder sitting under a different brand name in the parts list. The cylinder dictates the keyway, the tailpiece dictates the fit.

Outside of cylinders and keying, mixing is a different matter. Chassis parts, latch assemblies, rods and dogging components are family specific, and a part from one exit device series will not serve another even where it looks similar.

How Do You Confirm a Falcon Part Before You Order It?

Four pieces of information settle almost every Falcon order. Collect them before you search.

Fire rated openings add one more step. Confirm the rating from the label on the door edge, because fire configurations exclude dogging and insist on positive latching, and those two facts rule several otherwise identical parts out.

Where to Start for Each Falcon Family

Once you know the family, go straight to the part level rather than browsing. The Falcon replacement parts section is the starting point, and the family guides go deeper.

For egress hardware, use the 19, 24 and 25 Series parts guide alongside the exit device parts section. For cylindrical locks, the T Series guide and the cylindrical lock parts section. For deadbolt cylinders and keying parts, the Q500 parts guide and the deadlock parts section.

If you have a Falcon part number already, the parts by brand index and the full products and parts index will take you to the item directly.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

If the stamping on the device is unreadable or the series is not obvious, contact us with a photograph of the chassis and the door type, and we will confirm the family before you order.

Quick Summary

A strike plate costs a fraction of what the lock costs and decides whether the lock works. It is also the part most likely to have been replaced by whatever was in the van, which is why so many doors have a strike that nearly fits.

This guide covers what the strike does, the types you will meet, how to work out which one an opening needs, and why most strike problems are not actually the strike. For the part level breakdown, see our strike plates and deadlatches parts guide.

What Is a Strike Plate and What Does It Do?

The strike plate is the metal plate fitted into the frame opposite the lock. It has an opening in it that the latch bolt or deadbolt enters when the door closes, and it is screwed into the jamb so that it sits flush with the frame face.

It does three jobs at once.

• It guides the latch. As the door swings closed, the sloped face of the latch runs along the lip of the strike and is pushed back into the lock. When it reaches the opening, it springs out again and the door is latched.
• It takes the load. Everything the door does, every slam, every pull against the lock, every attempt to force it, lands on the strike and its screws.
• It protects the frame. Without a plate, the latch would be hammering wood or thin steel on every cycle.

That first job explains why the lip exists and why its length matters so much.

What Is the Lip on a Strike Plate and Why Does Length Matter?

The lip is the curved tab that extends from the faceplate out over the edge of the frame. It is the ramp that pushes the latch back as the door closes.

Lip length is measured from the centre line of the strike to the end of the lip, and it is not a style choice. It has to be long enough that the latch meets it rather than meeting the frame or the architrave, and short enough that it does not project into the opening where people walk past it.

Get it too short and the latch catches on the frame edge instead of riding over the lip, so the door bangs rather than closing. Get it too long and the lip sticks out into the traffic, snags clothing, and gets bent by trolleys until it no longer guides anything.

This is why you will see the same strike offered in a range of lip lengths as separate part numbers. A T shaped square corner strike with a plastic box might be stocked in half a dozen lip lengths, and they are not interchangeable once the frame is built.

What Are the Different Types of Strike Plate?

These are not interchangeable. The frame has been prepared for one shape, and fitting a different one means either a visible gap or cutting the frame. On a rated opening, cutting the frame is not a casual decision at all.

The ANSI pattern is the one worth knowing because it is the common denominator. A frame prepped to the ANSI strike pattern will take any strike built to it, which is precisely the point of having a standard.

Does the Box Behind the Strike Matter?

Yes, more than most people expect.

Behind the opening in the strike there is a cavity in the frame. A box, sometimes called a dust box, lines that cavity. Its obvious job is keeping mortar, insulation and debris out of the space the latch has to enter, because a latch that cannot fully extend is a latch that can be pushed back.

Its less obvious job is resistance. Strikes are stocked both with plastic boxes and with metal boxes, and that is a deliberate difference. A plastic box is fine on an interior door where nothing is going to be attacked. On an exterior door or anything protecting value, a metal box adds real resistance behind the plate rather than just keeping the hole tidy.

When you order a strike, check whether the box is included and which kind it is. The part number usually tells you.

Why Will My Door Not Latch? Strike Alignment Explained

This is the complaint behind most strike work, and the first test takes ten seconds.

Open the door and operate the latch by hand. If the latch extends and retracts freely with the door open, the lock is fine. The problem is between the latch and the strike. If it binds with the door open, the problem is in the lock or the door prep and the strike is innocent.

Assuming the lock is fine, there are three ways the alignment can be out.

The marks tell you the direction. A strike face with a bright wear line above the opening is a door that has dropped, and the fix is at the hinges, not at the strike. Filing the strike opening bigger to accommodate a sagging door is the repair that comes back.

When Moving the Strike Is the Right Answer

Sometimes it genuinely is. Frames settle, buildings move, and a strike fitted square to a frame thirty years ago may no longer be square to the door. In that case the strike is relocated properly, with the old fixing holes filled so the new screws bite into solid material rather than spinning in enlarged holes.

What is not a repair is packing the strike out with washers, or enlarging the opening with a file until the latch finds its way in. Both work for a while and both leave an opening that is easier to force than it was.

What Is a Rabbeted Strike and When Do You Need One?

A rabbeted frame has the door stop formed as a step in the frame section rather than planted on as a separate strip. The door sits into that step when it closes.

A flat strike cannot follow that profile. Fitted into a rabbeted frame it either stands proud of the step or leaves the latch meeting a corner, and neither works. A rabbeted strike is stepped to match, so its face follows the frame and the latch meets a continuous surface.

You can identify a rabbeted frame in a second by looking at the jamb with the door open. If the stop is a separate piece of timber or steel pinned on, the frame is not rabbeted. If the stop is part of the same section, stepping back from the face, it is.

Getting this wrong is common on replacements, because a flat strike will physically screw into a rabbeted frame. It just will not latch reliably, and the symptom looks like an alignment fault rather than the wrong part.

Why the Screws Matter as Much as the Plate

A strike is only as good as what is holding it in, and this is where most of the real security is won or lost on an exterior door.

Short screws reach into the frame skin and nothing else. Under a kick, the screws tear through thin material and the whole strike comes away with a section of jamb, regardless of how strong the lock was. Longer fixings that reach past the frame into the structure behind change what has to fail before the door opens.

Three things worth checking on any strike you are working on:

• Are the existing holes still sound, or have they been enlarged by previous adjustment so the screws no longer bite.
• Is the strike sitting flat, or has it been packed out with washers to cover an alignment problem.
• Is the frame reinforced behind the strike, which on hollow metal usually means a strike reinforcement rather than bare skin.

None of that is expensive. All of it is invisible once the door is shut, which is why it gets skipped.

What Should You Check on a Strike During Routine Maintenance?

1. Look for wear marks on the strike face, which show the latch is not arriving where it should.
2. Check the lip is straight and has not been bent by trolleys or carts.
3. Test the latch from a slow close, not a slam, because a slammed door will latch over a fault that a gentle close will not.
4. Check the deadlatch lands on the strike face, not in the opening, on locks that have one.
5. Check the screws are tight and that the holes have not opened up.
6. Look into the box for debris, particularly on doors near building work.

The slow close test is the useful one. Most doors that have a developing strike problem will still latch if you let them slam, so a quick check during a walk round misses it. Close the door gently and see whether it latches on its own.

Strikes, Deadlatches and Electric Strikes

Three things get called strikes and they are not the same.

• A strike plate is passive. It is a shaped piece of metal with no moving parts.
• A deadlatch is part of the lock, not the frame. It is the small plunger beside the main latch that stops the latch being pushed back once the door is closed. If the deadlatch misses the strike face it is not doing its job, which is another reason strike alignment matters.
• An electric strike replaces the passive plate with a powered one that can release the latch on a signal. That is a different product with wiring, handing and fail safe or fail secure behaviour to decide.

For the powered version, see our electric strike schematic diagram and the electric strike parts section.

What to Confirm Before Ordering a Strike Plate

1. The frame prep, which decides the shape: ANSI, square corner, T or rabbeted.
2. Faceplate dimensions, measured off the existing plate.
3. Lip length, measured from the centre line to the end of the lip.
4. Whether a box is included, and whether it should be plastic or metal.
5. What the strike has to receive, a latch bolt, a deadbolt, or both.
6. The finish, matched to the rest of the hardware on the opening.

Browse cylindrical lock parts and mortise lock parts for the locks these strikes serve, or the full products and parts index if you already have a part number.

About the Author

Security Parts has supplied repair parts for commercial door hardware since 2001, covering Von Duprin, LCN, Schlage, Falcon, Detex and Adams Rite at the component level. Our diagram based lookup exists so a technician can confirm a part before ordering it. This guide was written by the Security Parts team from supplier documentation and the questions our customers bring us.

For related reading, see our commercial door hardware troubleshooting guide and the commercial door hardware finish guide.

Quick Summary

The reader is the part of an access control system everybody sees and the part that does the least thinking. Understanding that split explains most of what is confusing about specifying one.

This guide covers what a proximity reader actually does, how mounting and technology are separate decisions, and what to confirm before ordering. For how the reader fits into the rest of the opening, see our access control and door hardware integration guide.

How Does a Proximity Card Reader Work?

A proximity reader emits a field. When a card or fob enters that field, the credential draws enough energy from it to power itself and transmit its number back. The reader picks up that number and passes it on.

Two things follow from that and both matter in practice.

First, the credential has no battery. It is powered entirely by the reader's field, which is why a card works for years and why it stops working at a distance. Range is a property of the field, not of the card.

Second, the reader is not making a decision. It reads a number and sends it to the controller. The controller holds the list of who is permitted, checks the number against it, and decides whether to release the door. If the door does not open, the reader is usually not the thing that refused.