Glossary of Terms
Alike Change –(see "keyed alike")
Anti-drill Plate –Steel plate with sufficient hardness to resist penetration by a HSS drill bit
Anti-Pick –Feature built into locking mechanisms to prevent unauthorized access
Anti-thrust Action –Latch action in which the latch bolt, when fully thrown, resists being forced back by end pressure
Anti-thrust Bolt –Spring actuated bolt which cannot be pushed back once it has been fully thrown into a correctly positioned locking plate
Anti-thrust Slide / Snib Bolt –Component which contacts the locking plate to activate the anti-thrust bolt mechanism
Armoured Padlock/Anvil Padlock –Square brass Padlock shrouded with steel body. Cylinder key operated.
Armoured Rose –Cylinder rose with features to protect it from physical attack
Backset –Distance from the outer face of the forend (or faceplate if fitted) to the centre-line of the keyhole and/or follower
Ball Locking –A method of locking used in high security padlocks. Hardened steel ball bearings are pushed outwards to engage with round indents on the shackle
Bathroom Lock –Privacy lock with latch bolt operated by lever handle or knob from both sides, and an additional deadbolt operated by thumb slide, thumb turn etc. from inside only
Blank (of key) –Key which has not been cut
Body –The main section of a product usually containing the working mechanism
Bolt (part of lock or latch) –Moving part of a lock or latch that provides engagement between leaf and frame (see also EN 12209)
Bolt-through Fixing –Method of attachment whereby the fixing means pass right through the door, window etc.
Bolt Thrower –Component within a Mortice Lock enabling greater projection of its deadbolt through the turn of its key.
Bottom Pin / Pin –Pin of a cylinder mechanism that is located in the plug and makes contact with the key
Bow (of key) –Enlarged portion of key at end remote from blade/bit
Box Lock –Cabinet lock designed for flush fitting into the edge of a box. A specifically designed staple is fitted to the box lid forming part of the locking mechanism
BS 3621:2007 –British Standard relating to Mortice Locks also known as "Thief Resistant Lock Assembly - Key Egress". Lock mechanism maybe either 5 Lever or Cylinder. The lock is often referred to as a "Kite Marked" Mortice Lock.
BS 8621:2007 –British Standard relating to Mortice Locks also known as "Thief Resistant Lock Assembly - Keyless Egress". Lock mechanism is Cylinder operated with a Thumb Turn on the inside of a door for easy egress. The lock is often referred to as a "Kite Marked" Mortice Lock.
BS 10621: 2007 –British Standard relating to Multi-point Locks also known as "Thief Resistant Dual Mode Lock Assembly"
Budget Lock –Rim fixed lock suitable for cabinets requiring little security. Operated by a square key.
Bullet Lock –Cylinder operated lock suitable for locking Roller Shutters
Bullet Lock Housing –Surface fixed lock housing providing
Burr –Plug which closes off the outer end of an individual pin chamber in a cylinder housing
Bush & Slide –Keyhole Cover for "Old English" Padlock preventing ingress of matter.
Cabinet Lock –Generic term for a variety of locks fitted to items of furniture such as cupboards, drawers, chests, boxes etc.
Cam –Component attached to the end of a cylinder plug to transmit locking/unlocking movement
Cam Lock –Cylinder lock where the cam serves as the bolt
Case –(see "lock case")
Change (of key) –(see "differ")
Change Key –Alternative term for either "servant key" or "changing key"
Claw Bolt –Pivoting claw-shaped element of a deadbolt, which serves as an anti-separation point when locked, but which withdraws fully into the lockcase when unlocked
Claw Bolt Lock –Lock comprising at least two claw bolts moving in opposite directions
Close Shackle Padlock –Padlock with most of the shackle concealed within the body
Cupboard Lock –Cabinet lock designed for surface fitting onto a cupboard door
Cut Cupboard Lock / Cut Cabinet Lock –Cabinet lock designed for flush fitting which is cut into the edge/rear face of the door
Cycle –(see "test cycle")
Cylinder –Self-contained assembly comprising at least one cylinder mechanism and the output drive element (see also EN 1303)
Cylinder Housing –Main body of cylinder
Cylinder Key –Key for use in a cylinder lock
Cylinder Latch –Latch operated by a cylinder
Cylinder Lock –Lock comprising one or more cylinders
Cylinder Night Latch –Night latch operated by a cylinder (see also "EN 12209")
Cylinder Padlock –Padlock operated by a cylinder
Cylinder Pin Tumbler Lock –Cylinder lock with pin tumbler detaining elements
Cylinder Pull –Shaped plate for fitting under the flange of a rim cylinder to provide the means to pull the door leaf using fingers
Cylinder Rose / Cylinder Ring –Substantial circular ring which surrounds the outer end of a cylinder at the surface of the leaf for decorative and/or security purposes
Dead Latch –(see "deadlocking latch")
Deadbolt –Bolt of a lock that is moved in both locking and unlocking directions by means of a key or thumb turn
Deadbolt Projection –The amount that the bolt of a lock is moved in its locking direction by means of a key or thumb turn
Deadlock –Lock with a deadbolt only
Deadlocked –Locked in such a way that movement of the bolt towards its unlocked position is positively prevented
Deadlocking –Capable of being deadlocked
Deadlocking Latch –Latch with a bolt that can be deadlocked
Detainer –Element of a lock mechanism, similar to a lever, that makes contact with the key
Differ –Variation between lock mechanisms of similar design due to differences in the lift and/or position of the detaining elements
Differ Bit –Intermediate element resulting from pin being split for the purpose of master keying
Differ Step –Step on the key bit of a lever lock that makes direct contact with, and lifts, a particular detaining element
Distance to Pin –Specific measurement of a lock referring to the distance between the edge of the lock and its drill-pin upon which a "pipe" type key would sit.
DIN Cylinder –(see "Euro Profile cylinder")
Double Throw Lock –Lock requiring two full turns of the key to fully throw the deadbolt
Draw Back Lock –Lock in which the spring bolt is withdrawn by a sliding handle
Drawer Lock –Lock for use on a drawer
Drug Cupboard Lock –Heavy type of cupboard lock used specifically for situations where greater security is required e.g. Drugs.
Emergency Exit Device –Door locking arrangement that allows keyless egress at all times, using one simple hand movement, although this may require prior knowledge of its operation (see also EN 179 and EN 1125)
Escape Lock –Lock that allows keyless egress at all times, using one simple hand movement, without the need for prior knowledge of its operation
Escutcheon –Component which surrounds the entrance to a keyhole at the surface of the leaf, for (mainly) decorative purposes (see also EN 1906)
Euro Profile Cylinder / DIN Cylinder –Profile cylinder for which the cross-section of the housing is to the standard European profile
Faceplate / Face Plate / Outer Forend –Additional plate mounted over forend for decorative purposes
Follower –Component that transmits rotational movement from a spindle (linked to the handle/knob) to the latch bolt, to withdraw it against spring force
Forend / Fore End / Inner Forend –Long narrow plate attached to, but extending beyond, the lockcase, for mounting purposes (see also EN 12209)
Galvanised Padlock –Term sometimes used to describe an "Old English" Padlock referring to its appearance
Grand Master Key –Key that operates locks of all combinations in a suite, including those in lower level suites under separate submaster keys
Handed –Restricted to one particular closing direction only (either clockwise closing only or anti-clockwise closing only)
Handing –Property relating to the direction a leaf rotates to close
Hardening –Heat treatment of lock components used to increase security against attack e.g. drilling
Hasp/Staple –A hinged metal strap used in conjunction with a padlock to secure doors and gates
Hook Bolt –Swing bolt in the shape of a hook
Horizontal Lock –Mortice or rim lock with the follower at the same height as the keyhole but further away from the forend
Keep / Staple –Alternative terms for "locking plate" or "striking plate" – but used, preferably, where there is no plate-like feature
Key –Instrument used to operate a lock, which can be removed and carried on the person
Key Blank –Key without steps
Key Bow –Part of the key that is held to operate it
Keyless Egress –Mechanism which allows the unlocking of a lock without a key usually by a thumb turn or handle
Key Registration –Control of key combinations to prevent unauthorized duplication of keys
Key Retention/Key Retaining –A mechanism preventing the removal of a key from a lock usually unless it is locked
Keyed Alike –Operable with the same key
Keys to Pass –(see "keyed alike")
Laminated Padlock –Padlock whose body is made up of a series of flat pieces of metal riveted together
Laminated Safe Lock –Safe lock whose body is made up of a series of flat pieces of metal riveted together
Latch –Self-engaging fastener which secures the leaf of a door or window in the closed position, and which can be released by hand
Latch Bolt –Bolt which, by virtue of its shape and the forces acting on it, engages automatically with the locking plate as the door is closed
Left Hand Door –Door which opens in a clockwise direction when viewed from above
Lever –Element of a lock mechanism, similar to a detainer, that makes contact with the key
Lever Mechanism –Lock mechanism comprising one or more levers
Lock –Device for securing a door or window in the closed position, where unlocking movement of the bolt is by means of a differ key from at least one side
Lock Case –Cylinder mortice lock without the cylinder
Locker Lock –Steel bodied surface fixing lock operated by either a lever or cylinder mechanism suitable for use on steel cabinets
Locking Plate –Generally accepted term for any component that engages the bolt or bolts of a lock (i.e. it includes striking plate, keep and staple)
Locking Snib –Hand operated device for preventing a bolt from being thrown or withdrawn, or to change the function of a lock or latch without dismantling
Magazine Lock –Very heavy brass Rim Lock specifically designed for use by military bodies (particularly naval) for security of ammunition etc.
Master Key –Key that operates locks of all combinations within a particular suite
Master Keyed Suite –Set of locks and/or padlocks related by a common key, or keys
Microswitch –Device providing indication of the
Mortice Cupboard Lock –Cabinet lock designed for mortice fitting into the edge of a cupboard door
Mortice Cylinder –Cylinder for use with a mortice lock
Mortice deadlock –Deadlock adapted for flush fitting into a mortice
Mortice Latch –Latch adapted for flush fitting into a mortice
Mortice Lock –Lock adapted for flush fitting into a mortice
Mortice Night Latch –Night latch adapted for flush fitting into a mortice
Mushroom Roller / Mushroom Driver –Top pin with undercut groove which when under-lifted allows the plug to rotate a small amount thereby frustrating attempts to pick the cylinder
Narrow Stile Lock –Mortice lock with a case depth of less that 67mm
Night Latch –Lock with automatic bolt which is withdrawn from outside by key, and from inside by handle or knob
Non-handed –Not restricted to one particular closing direction only (either clockwise closing only or anti-clockwise closing only)
Old-English Padlock –Traditional lever operated Padlock with a steel body/shackle construction
Open Shackle Padlock –Padlock in which a complete 180° hoop of shackle is exposed
Oval Profile Cylinder –Profile cylinder for which the cross-section of the housing is oval
Padlock –Detachable and portable locking device which uses a shackle to link itself to an object, or link objects together (see also EN 12320)
Panel Lock –Two-bolt upright lock for use on metal casement doors
Panic Bar –Horizontal bar of a panic exit device which is used to activate the mechanism (see also EN 1125)
Panic Bolt(s) –(see "panic exit device")
Panic Exit –Egress point on an escape route that is likely to encounter a panic situation
Panic Exit Device –Door locking arrangement that allows egress under all conditions in response to light pressure anywhere along a horizontal bar running the width of the door (see also EN 179 and EN 1125)
Panic Latch –Latch which is released by pressure anywhere along a horizontal bar running the width of the door
Pin Key –A key used to operate a lever lock which does not have a drill-pin
Pin / Pin Tumbler –Cylindrical-shaped detaining element of a cylinder mechanism that it is positioned by the key as it is inserted
Pin Tumbler Mechanism –Locking mechanism in which the principal detaining elements are a pins
Pipe Key –A key used to operate a lever lock which has a drill-pin
Plug –Rotating part of a cylinder lock containing the pins, and into which the key is inserted (see also EN 1303)
Privacy Lock –Lock that is lockable from the inside only
Profile Cylinder –Mortice cylinder with constant cross-section housing
Push-bar –Horizontal bar of a panic exit device (see also EN 1125)
Rebate –Step in a frame (or adjacent leaf) which provides the stop for the leaf
Rebated Lock –Lock adapted to mount on the rebated edge of a leaf
Reversible Bolt –Bolt for which the closing direction (clockwise or anticlockwise) can be altered without dismantling
Right Hand Door –Door which opens in an anti-clockwise direction when viewed from above
Rim Cylinder –Cylinder for use with a rim lock or latch, and which is adapted for flush (or near flush) mounting within a leaf
Rim Deadlock –Deadlock adapted for surface mounting on the face of a leaf
Rim Latch –Latch adapted for surface mounting on the face of a leaf
Rim Lock –Lock adapted for surface mounting on the face of a leaf
Rim Night Latch –Night latch adapted for surface mounting on the face of a door leaf
Roller Bolt –Latch bolt with rotating feature in the head to facilitate withdrawal of the bolt upon engagement with the striking plate
Sash Lock –Alternative term for an upright mortice lock
Scandinavian Oval –Mortice cylinder with oval cross-section housing, attached to the lockcase using bolt through fixings
Screwed Cylinder –Mortice cylinder with threaded housing
Security Cylinder –Cylinder with a high level of resistance to attack methods
Security Escutcheon –Escutcheon with a high level of resistance to attack methods
Servant Key –Key that operates one particular lock in a master keyed suite
Shackle –The 'U' shaped metal bar on a padlock which forms the lockable link to another object (or other objects) (see also EN 12320)
Shear Line –Line representing the cylindrical surface of the plug in a pin tumbler cylinder
Shutter Lock / Roller Shutter Lock –Steel surface mounted lock used to secure Roller Shutters by means of sideways movement of its bolts
Side Bar –Element of a pin tumbler cylinder that only allows the plug to rotate when all the pin tumblers are correctly positioned
Sliding Door –Door with one or more leaves which move horizontally in their own plane
Snaplock –Method of locking a padlock without the use of a key by pushing the shackle into the body
Spindle –Bar (usually of square cross-section) that transmits the rotational movement of lever handles/knobs on either or both sides of a door leaf to the follower of a latch (see also EN 1906)
Split Follower / Divided Follower –Two-part follower that enables movement from handles/knobs on opposite side of a door leaf to be transmitted independently
Spring Bolt –Latch bolt operated by a spring
Spring Shackle Padlock –Padlock with shackle that springs open when unlocked, and which closes without the use of a key
Straight Cabinet Lock/Straight Cupboard Lock –Lock adapted to lie flat on inside face of cabinet or cupboard door
Sprung –Hardware containing a spring mechanism which enables the door handle to return to the horizontal position after use
Striking Plate / Strike Plate / Striker –Component that engages and operates a latch bolt
Sub-grand Master Key –Key which will operate all locks in a one level down subsuite of a great grand master-keyed suite
Sub-master Key –Key which will operate all locks in a one level down subsuite of a grand master-keyed suite
Suited –Belonging to a master keyed suite surface mounted door closer door closer mounted on the face of the door or door frame
Thrower –Component of a lever lock mechanism that rotates with the key and engages with the bolt to move it
Thumb Turn –Small handle or knob for operation by thumb and forefinger (see also EN 1906)
Till Lock –Lock for use on a drawer
Top Pin / Driver / Roller –Pin of a cylinder mechanism that is located in the cylinder body and is acted on by a spring
2 Way Keyhole –Characteristic of a lock which allows both down-shoot and across-shoot of its deadbolt
Unsprung –Hardware that does not containing a spring mechanism to automatically return the handle to the horizontal position after use