Unsure of some of the terms we use within our product range? Whether it's an 'auxiliary lock' or 'BS2621', this glossary of industry terms should clear up any jargon and help you understand some of the more complicated ironmongery terminology.


Access Control Cylinder - A replacement for a mechanical cylinder which incorporates electronic access control and allows the original host lock to function without additional wiring or hardware modifications.

Anti Ligature - Devices or hardware that are designed to eliminate points of ligature and prevent self harm. Commonly used in places where individuals are a higher risk such as mental heath facilities.

Aperture - In ironmongery terms, 'aperture' is used to distinguish between the external dimensions of a letterplate, and the dimensions of the opening (or aperture).

Architectural Hardware - Sometimes described as "door furniture", such items include door handles, locks, closers and hinges.

Auxiliary Dead Latch - A supplementary latch in a lock which automatically deadlocks the main latch bolt when the door is closed. Also known as auxiliary latch bolt; deadlocking latch bolt; trigger bolt.

Auxiliary Lock - A lock which has a latch bolt or a dead bolt and is operated by a key or a thumbturn or both. Often used in addition to another lock.


Backplate - The plate onto which either a handle or a mortice knob is mounted.

Backset - The distance from the edge of the door to the centreline of the cylinder at the centreline of the door thickness.

BS3621 - The most popular standard for locks on doors. For a lock to meet this standard it must have the ability to be deadlocked and the key removed from both sides so that no one can gain access or exit the door without a key.

Butt Hinge - The most popular type of hinge, composed of two plates attached to abutting surfaces of a door and door jamb and joined by a pin.


Case - The housing of a lock.

Combination Lock - A lock that can only be opened by using a particular combination of numbers of letters.

Cylindrical Lock - A lock that is designed to be installed through the door with a knob or lever on either side, that retracts the latch when turned. Commonly found in homes, offices, and interior doors.


Deadbolt - A lock that is designed to be morticed into the door and operated by a Spindle and Thumbturn rather than a key.

Deadlock - A lock that is designed to be morticed into the door and operated by a key from either side and offers additional security.

Door Closer - A device used for controlling the speed and force of a closing door, usually hydraulic (liquid) or pneumatic (gas) operated.


Escutcheon - Otherwise known as a keyhole cover, escutcheons are fitted over/around the keyhole to match the rest of the door furniture. You can get open or covered escutcheons.


Jamb (or Door Jamb) - The vertical section of the doorframe which a door is secured onto.


Keyed Alike - Refers to a group of locks that operate from the same key.


Latch Bolt - A lock component which protrudes from or is withdrawn into the lock front by action of the lock mechanism. When the door is closed and the dead bolt thrown, it extends into a hole provided in the strike thus locking the door. It does not retract with end pressure.


Mortice - A hole or pocket cut into a door or window to accommodate a lock or latch mechanism

Mortice Lock - A lock that requires a pocket - the mortice - to be cut into the door where the lock is to be fitted, common in commercial construction.


PVCU - Unplasticised Polyvinyl Chloride. A hard, durable plastic used throughout the construction industry. Healthier for humans than the plasticised PVC, since it’s the plasticisers that cause problems. 


Rim Knob - A pair of door knobs designed specifically to fit onto a Rim Latch. The main difference is that only one of the knobs will have a Rose Plate, the other fits directly onto the Rim Latch.

Rim Lock - A locking device externally mounted on the door, which provides the most basic security.

Rose - A small symmetrical (round or square) plate to which the lever handle or doorknob is affixed and which is then affixed to the door. Considered more modern than a standard back plate.


Sash Lock - A sashlock is a mortice lock which combines a latch (operated by a pair of handles or door knobs) to open/close the door, and a key-operated deadbolt which locks/unlocks the door.

Standard Profile - A term referring to the keyhole shape which is most commonly used throughout the UK. The Standard Profile is a small sized hole for a standard UK stem key to be inserted.

Strike Plate - A flat plate that is fitted to the door frame and designed to accept and hold a latch or deadbolt of any latch or lock as the door closes.


Tubular Mortice Latch - A tubular latch is a compact and efficient latch, morticed into the door and operated by a pair of lever handles or door knobs. Ideal for internal doors which need to be closed but are never locked.

Turn and Release - Used with a bathroom mortice lock to operate the deadbolt instead of a key, in order to provide privacy. The bathroom door is locked from the inside by the thumb turn. From the outside a coin release will unlock the door in case of emergency.


5 pin / 6 pin / 10 pin - Refers to the number of pins used in a cylinder lock mechanism. Generally, the more pins used the more secure the lock is.


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