The Schlage 35-003 is the OEM Everest Full Size Interchangeable Core (FSIC) control key blank, "Do Not Duplicate," embossed, 6-pin, sold in a 50-pack. It is documented in the Schlage Key Systems Cylinders and Keys Catalog and is used to insert and remove Schlage Full Size Interchangeable Cores into locks and cylinder housings. Available in 24 Everest 29 keyway configurations: C000, C100, C123, C124, C125, C134, C135, C145, C150, C200, C230, C234, C235, C245, C345, D120, D124, D125, D134, D135, D145, D150, D234, and D235. Keyway must be specified at time of order.

The 35-003 is a blank- it requires cutting to the control bitting for the specific core system before use. It does not open locks. This is the core-handling key, not the operating key.

What a Schlage Control Key Does

In any Schlage FSIC installation, the interchangeable core (IC) is the removable plug inside the lock housing. The core contains the pin stacks, key profile, and bitting that defines which operating key opens the lock. The core can be removed from the housing without disassembling the lock from the door- which is the primary advantage of IC systems over conventional fixed cylinders.

The control key is the tool that manages the core itself. Inserting the 35-003 control key (cut to the correct control bitting) into the IC core and rotating it to the control position- typically 15 degrees- releases the core's locking bars from the housing retaining slots. The core can then be extracted from the housing. A replacement or rekeyed core is inserted and locked into the housing with the same control key rotation in the opposite direction.

This entire rekeying procedure takes under a minute per lock and requires no tools beyond the control key. No screwdrivers, no lock disassembly, no calling a locksmith to the door. This is the operational value of FSIC systems in large commercial facilities- a university can rekey 200 doors after a key loss incident in hours rather than days.

Why the Control Key Says "Do Not Duplicate"

The "Do Not Duplicate" embossing on the 35-003 is not decorative. A control key in the wrong hands compromises the entire key control system because the holder can extract cores from every lock in the facility and replace them with unauthorized cores. Any locksmith or key cutting service presented with a 35-003 blank should refuse to duplicate it without Allegion authorization.

The Everest 29 keyway restriction adds a second layer of protection. Everest keyway blanks are only available through authorized Allegion distribution channels- they are not stocked at hardware stores, big box retailers, or most locksmiths. Even if someone finds a 35-003, the Everest profile prevents duplication at unauthorized sources. The combination of restricted blank availability and DND embossing is what makes Everest control keys a meaningful key control tool rather than just a visual deterrent.

Schlage 35-003: Keyway Selection Across 24 Everest Options

The 24 keyway options on the 35-003 correspond to Schlage's Everest 29 sectional keyway family. The C series (C000 through C345) and D series (D120 through D235) are the two major groups. Within each group, the number suffix identifies the specific sectional keyway profile- C123 and C234 are different profiles and are not interchangeable.

The control key blank must match the keyway of the installed FSIC cylinders exactly. A 35-003-C123 blank fits C123 cylinders and does not fit C234 cylinders. Confirm the installed keyway from the original Allegion project documentation or the key system specification sheet before ordering.

The 35-003 covers the Classic Family standard FSIC cores. It does not apply to Primus, Primus XP, or SFIC (Small Format Interchangeable Core) systems- those use different control key blanks.