The door hardware industry, like many others, uses very specific terminology to describe its products and their modes of operation. Knowing and using the correct terms helps ensure building and property security and can even save lives. The list below can help you communicate clearly with others in our field.
Active Door (in a pair of doors) - The leaf that opens first and the one to which the lock is applied
BHMA - The Builders Hardware Manufacturers Association (BHMA) is the trade association for North American manufacturers of commercial builders hardware
Current - The flow of electricity through a conductor measured in amps
Dead Bolt - A lock component which projects from, and is withdrawn into, the lock case by action of the lock mechanism. When the door is closed and the dead bolt thrown, it extends into the strike, locks the door, and does not release with end pressure
Delayed Egress - An irreversible time delay built in the locking device of an opening preventing immediate egress. Detex abbreviation: EE
Dogging Device - As used in exit devices, a mechanism that fastens the cross bar in the fully depressed position, and also retains the latch bolt or bolts in a retracted position, thus permitting free operation of the door from either side
Exit Device - A door-locking device designed to grant instant exit by pressing on a cross bar that releases the locking bolt or latch
Fail Safe - A term used to describe an electric lock that has a mechanical state of beingunlocked and requires power to lock it. Also known as electrically locked. Detex abbreviation: FSA
Fail Secure - A term used to describe an electric lock that has a mechanical state of being locked and requires power to unlock it. Also known as electrically unlocked. Detex abbreviation: FSE
Want to know the difference between Fail Safe and Fail Secure? Read our article on the differences here.
Keystop - A pertusion that prevents a key from moving past a particular point on a locking device. Also known as Key Retention
Mullion - A vertical member in an opening for two doors permitting each door to be operated and latched independently. The mullion may be removable or fixed
Strike - A metal plate or box that is pierced or recessed to receive the bolt or latch when projected
Trim - Trim is composed of both operating and non-operating decorative elements and includes knobs, levers, pulls, roses, escutcheons, lock fronts, strikes, actuating bars, turns, thumb pieces, vertical rods, cylinder assemblies, and covers