Glossary

Industry terminology explained......

Automatic Deadlatch

The main bolt is automatically locked when the door is closed.

Backplate

The plate is fixed on a door to which the lock is attached.

Backset

The horizontal distance from the forend face to the key hole and / or follower.

Bathroom Lock

A lock with furniture operated latch bolt and a deadbolt which is only operated from inside (usually with a thumb turn).

Bit (Key Bit)

That part of a mortice key which is cut.

Blade

That part of a cylinder blank key that is cut.

Blank

An uncut key.

Bolt

The part of the lock which extends into the frame to secure the door or window.

Bow

The handle or head of a key blank.

Box Strike Plate

A strike plate with a box shape around the bolt hole.

Bush

A lining (usually brass) around the key or follower hole which allows smoother operation and protects the moving parts of the lock from wearing.

Cabinet Lock

A generic term for locks used on drawers, cupboards and boxes.

Centers

The vertical measurement between the centre of the key hole and the centre of the follower hole on a sash lock.

Class Room Function

The thumb turn can be rotated into one direction only by using a ratchet mechanism in the turn side of the cylinder. You can only unlock the door from inside, this ensures that someone inside the room cannot lock anybody out but can always escape in a case of emergency.

Claw Bolt

Pivoted claws on a deadlock which swing out sideways when the bolt is extended; these are usually used on sliding doors.

Clutch Release Function

When the key is inserted in disengages the thumb turn by use of a clutch mechanism. This allows the door to be unlocked even if the thumb turn is being held in the locked position from the inside. It is ideal for places where a non-key holder could hold the thumb turn in the locked position to prevent the door being unlocked.

Common Entrance

This system is widely used in apartments, office blocks and hotels. Each apartment or office has its own individual key which will not operate the lock of any other in the building. It will however operate the communal entry doors and other service areas.

Construction Keying

Construction keying allows the contractor a full access during the construction period. The mechanism is activated by first insertion and rotation of a master key, once this is done it disenables the construction key and enables the master key to operate.

Cupboard Lock

A generic term for locks used on drawers, cupboards and boxes.

Cut Cabinet Lock

The flange of a cut lock is recessed into the edge of the door / drawer.

Cut Cupboard Lock

The flange of a cut lock is recessed into the edge of the door / drawer.

Cylinder Rose

A ring wish usually fits around the face a rim or screw-in cylinder giving a tidier aesthetic appearance.

Deadlatch

A nightlatch or latch, the latch of which can be locked.

Differs

This is the number of possible keying permutations available, i.e. the number of unique lock combinations available. The number of differs increases with the number of pins, levers and other variables on more complex locking products such as side bars and profiles.

Double Locking

Deadlocking facility is usually achieved by an opposite turn of the key in the outside cylinder. It gives protection against slipping and internal handle manipulation.

Driver

Also known as a top pin, this is the pin underneath the code pin which, when lined up (after the insertion of a key), forms the shear line that allows the key to rotate and therefore open the lock.

Escutcheon

A plate or rose which fits around a cylinder or key hole.

Follower

The square hole in a lock which accepts a spindle to which furniture is attached.

Forend

The front face of a lock.

Hook Bolt

Pivoted hook shaped bolt on a deadlock which swings down when operated; these are usually used on sliding doors.

Ingress Protection

Classifies and rates the degree of protection provided against the intrusion of solid objects, dust, accidental contact and water.

Keep

Another name for Strike Plate.

Key Bit

That part of a mortice key which is cut.

Key Blank

An uncut key.

Key Bow

The handle or head of a key blank.

Keyed Alike

Each lock is operated by the same key, an example of this could be that your front & back doors are operated by the same key for convenience.

Keyed To Differ

Each lock is operated by its own key, this key should not operate any other locks (bearing in mind that there is a finite number of keying combinations (differs) available)

Keyed To Pass

Another name for Keyed Alike

Keyhole

The hole in a lock or cylinder where the key is inserted.

Keyway

The hole in a lock or cylinder where the key is inserted.

Latch

The bull nosed spring bolt which is usually operated by furniture and used to hold the door closed but not lock it closed.

Lip

The flat surface on a striking plate where the latch or bolt first hits.

Master Key

A key that will open every lock in a Master Keyed System.

Master Keyed

Each lock is operated by its own key, this key should not operate any other locks however there is also a Master Key which will open any of the locks in the system. An example of this would be a block of flats where every tenant has their own key but the landlord has a single master key which will open any of the flats.

Mortise

A deep recess cut into wood for purposes such as for receiving a mortise lock.

Mushroom Pin

A pin shaped like a capital letter "i", it gives some protection from picking as the middle of the pin can lodge on the shear line stopping the cylinder from opening.

Nightlatch

A rim or mortice latch which shoots when the door is closed, there is often an internal button which allows the bolt to be held in either the extended or withdrawn position.

Rebate

A recess, groove or step of rectangular section, cut along the edge of a piece of timber to receive a mating piece.

Rebate Set

A rebated component set is used to convert a mortice lock with a flat forend, into a full rebated lock.

Rim Lock

A lock which is fitted to the inside face of a door.

Rose