By Kent · Lock Depot Staff Writer

Ask any facility manager what they hate about keys and you'll hear the same thing: every time someone quits or loses a key, a locksmith has to come pull cylinders and rekey the building. The small-format interchangeable core, SFIC, was built to end that. With a Best SFIC core and a control key, you swap the whole core out in about ten seconds without a screwdriver. This is the key-control system serious buildings run on. Here's what you're actually buying.

The control key is the trick

Every SFIC lock has a figure-eight-shaped core that drops into the lock body. A special control key, different from the everyday operating key, retracts a lug and lets you pull the entire core out in one motion, then drop a new one in. That's the magic. Someone loses a key? You don't rekey the lock. You pull the core, drop in a freshly pinned one, and the lost key is dead. Ten seconds a door, no locksmith call. Whoever holds the control key controls the building. Guard it like cash.

Uncombinated cores, buy them pinned or blank

The 1C7A1 is a 7-pin uncombinated core in the Best A keyway. "Uncombinated" means it ships blank, no key cuts assigned yet. That's what you want if you or your locksmith pin your own cores to your own key system. If you'd rather we combinate them to a bitting you supply, we can do that too. The 7-pin is the standard depth for real master-key systems; the 6-pin exists but 7-pin gives you far more room to build masters and change keys without collisions.

SFIC vs a standard cylinder, when it's worth it

For a house or a single door, SFIC is overkill and you don't need the control-key overhead. Where it pays off is any building with turnover: schools, medical offices, property management, anywhere staff and tenants change and keys wander. The upfront cost per opening is higher, the cores and the housings and the control system, but you make it back the first time you'd have paid a locksmith to rekey twenty doors and instead did it yourself over a lunch break. If you manage more than a handful of doors, run SFIC.

Housings have to match

The core is only half of it. The lock body, the lever, the mortise cylinder, the padlock, the exit trim, has to be prepped to accept a small-format interchangeable core. Locks come "SFIC-prepped" or "less core" for exactly this. Don't order cores for locks that aren't cut for them. When you buy the opening, buy the lock SFIC-prepped and the core to match, and tell us it's a Best small-format so we don't hand you a large-format (LFIC) core that won't seat.

Common questions

What does the control key do?

It removes the entire core from the lock in one motion, so you can swap cores in seconds instead of rekeying. It's separate from the everyday operating key and controls the whole system, keep it locked up.

What does "uncombinated" mean?

The core ships blank, with no key cuts assigned. You (or your locksmith) pin it to your own key system, or we can combinate it to a bitting you provide.

Is any Best core going to fit my keys?

Only if the keyway matches. Best offers many keyways; the A keyway is standard but restricted keyways won't accept an A core. Check the keyway on your existing key first.

Do I need special locks for these?

Yes. The lock body must be SFIC-prepped ("less core") to accept a small-format interchangeable core. Buy the locks prepped for it and the cores to match.

Lock Depot stocks Best SFIC cores uncombinated in the common finishes and keyways, plus SFIC-prepped locks and the control cores to run the system. Start at the Best SFIC hub, or if you're speccing the mortise locks those cores go into, read Which Sargent 8200 Mortise Lock for a School Corridor. Or call 877-365-5625 with your keyway and how many openings you run, and we'll size the core order and the control system.