A Comprehensive Glossary of Lock Picking / Lock Smithing Terms {144 Terms}

Here is the list of the most comprehensive Glossary of Lock picking with 144 terms included.


After the insertion and turning of keys in a lock, a mechanical process occurs that causes the opening of locks. It is known as action.

Alike Change

Opening of multiple locks with a single key after bringing modification in locks or key system.

All to Pass

A set of pins that are placed in a lock to enable it to open with any key is described with the term All to Pass.

Angled Cuts

Angled cuts refer to cuts made on a key blade that is not parallel to its length, but instead, are positioned at different angles to the right, left, and center of the blade.

Antidrill ball bearings/lunes/rods

Antidrill ball bearings/lunes/rods are small objects fitted in a cylinder before the first pin chamber in a lock to prevent shear line drilling.


A security feature in locks that prevents the bolt or latch from being disengaged by physical force, such as pushing or pulling, without the use of a key or combination.

Anti-Thrust Plate

A metal plate is mounted on the door frame behind a lock to prevent the lock bolt from being pushed back through physical force, providing an additional level of security.

Automatic Deadlatch

A lock that automatically locks itself when the door is closed, preventing the door from being easily opened from the outside without a key.


A metal plate is mounted on the inside of a door to provide a surface for a lock or handle to be attached.


The measurement of the distance between the edge of a door and the center of a lockset in a horizontal direction.

Barrel Key

A type of key that has a protruding bit located on the outside of a hollow, cylindrical shaft.

Bicentric Cylinder

A lock cylinder, typically featuring a pin tumbler mechanism that contains two sets of pin chambers and two plugs instead of the usual single set, enables it to be operated by two different keys.


A pin tumbler cylinder lock comprises two rows of pin tumblers arranged in parallel, as well as two sidebars that are actuated by a U-shaped key.

Binding Pin

A pin that is held firmly against the housing of a lock by the lock spring, creates resistance to turning.

Bump Key

A bump key is a type of key specially cut to allow for quick and easy opening of a lock through a technique known as bumping.


Bumping is a lock picking technique that involves using a bump key to forcefully and quickly jolt the pins inside a lock. This jolt causes the pins to jump, allowing the lock to be easily opened.

Bit Key

A type of key that has a projecting bit attached to a solid cylindrical shaft, which features cuts that are designed to bypass the wards or operate levers in the appropriate lock.

Bit Key Lock

A lock that employs bit keys and operates via a warded or lever mechanism.


The unique arrangement and cut of key pins and key grooves in a lock correspond to the shape of a specific key.


The part of the key that is inserted into the lock is called the blade or shank.


A key that has not yet been cut is called a blank key.


The part of a lock that is moved into a locked or unlocked position is called the bolt.

Bolt head

The portion of a bolt that protrudes beyond the case or forend of a lock is called the bolt head.

Bolt hole

The hole in a case, forend, plate, or staple of a lock that guides and/or allows the bolt to pass through is called the bolt hole.

Bolt stump

The part of a deadbolt or runner that protrudes and typically has a rectangular cross-section is called the bolt stump. This component passes through the slot or gating in the levers as the bolt moves.

Bottom pin

A pin tumbler lock component that sits below the shear line and is responsible for preventing the plug from rotating


The key handle.


A method of lock manipulation involves using a specially designed tool, known as a broach, to lift or manipulate the individual pins inside a lock.


Lock bypass is a technique used to open a lock without using the key by manipulating or circumventing the part of the lock mechanism that is typically operated by the key.

By-Pass Tool

A device that neutralizes the security of a locking device due to a weak design

 Combination Lock

A lock that requires a specific sequence of numbers or symbols to be dialed on a rotating dial or keypad in order to open

Cabinet Lock

A cabinet lock is a small, compact lock used to secure drawers, cabinets, and other types of storage units, typically with a simple key mechanism.


A cam is a rotating or sliding piece in a lock or other mechanical device that engages with another part to transmit motion or force. It is often used to control the locking and unlocking of a device or to provide a specific movement or action.

Cam Lock

A type of lock that uses a cam to secure the locking mechanism, commonly found in cabinets, drawers, and other low-security applications.


The body of a lock.

Case Ward

A protrusion in a lock case obstructs the rotation of an incorrectly shaped key, increasing security by limiting keyway access.

Change Index  

A small marking on a combination lock dial that indicates the position of the dial at which the combination may be changed.

Change Key 

A special key used to insert or remove lock cores from a lock housing. It typically only operates one specific type of lock core.

Changeable Lever

A lever that can be easily replaced or changed to accommodate different keying configurations in a lever tumbler lock.


A U-shaped metal fastener with holes at the ends for a bolt or pin to pass through, used for attaching rods or cables to machinery or vehicles.

Clover Leaf Cam

A type of cam with a shape resembling a clover leaf, used in cam locks to rotate the locking mechanism when a key is turned.


A series of numbers, letters, or symbols used to operate a lock or security system, often requiring specific knowledge or access to use.

Code Key Machine

A tool used to create an initial key when the specific depths and spacing of its cuts are already known.

Comb pick  

A tool shaped like a comb that is utilized to raise the pin tumblers in a cylinder above their typical shear line.

Control Key  

A specialized key designed to extract the core from an interchangeable core cylinder.

Control Shear Line

Control Shear Line refers to the separation point between the bottom pin and the master pin in a lock that allows the control lug of an interchangeable core to rotate and operate the lock. It is the line at which the shear line is separated when using a control key, allowing the core to be removed or installed.

Control Sleeve

A sleeve that surrounds the core of an interchangeable core lock, controlling access to the control lug.


A hole or opening that is drilled perpendicular to the surface of a door or cabinet to receive a lock or latch.

Cut Depth Number

A numerical value assigned to each cut on a key, representing the depth of the cut and determining the position of the corresponding pin in the lock cylinder.


The curtain is a component found in lever locks that acts as a security barrel, restricting access to the lever pack and serving as the bolt thrower.

Curtain pick

A specialized tool used in lock picking to manipulate the curtain of a lever lock, allowing access to the lever pack and subsequently opening the lock.


Cuts refer to the indentations or grooves on a key that correspond to the pins or tumblers in a lock

Cylinder Key

A key designed to operate a cylinder lock, typically with a cylindrical blade that fits into the keyway of the lock and has cuts along its length to correspond to the pins or tumblers inside the lock.

Cylindrical Lockset

A type of lockset in which the lock mechanism is housed in a cylindrical casing that is installed through a hole in the door.


A lock that is moved by the turn of a key or thumb turn without the use of a spring mechanism provides a higher level of security than a latch.


A type of latch commonly used in door locks that automatically deadlocks when the door is closed, preventing credit card and other bypass attacks.


A type of lock that can only be opened with a key, and which does not have a latch or handle to retract the bolt. The bolt is typically operated by a key or thumb turn.


The mechanism that prevents the bolt or latch from being retracted by force, such as when the door is being kicked or forced open.

Deadlocking Latch

Latchbolt having a deadlocking mechanism.

Depth Key

A key used to determine the depth of cuts needed for a new key to fit into a particular lock cylinder.

Double Acting Lever Tumbler

A lever tumbler lock mechanism that can be locked and unlocked by key from either side of the door, using two sets of levers that interact with the bolt.

Double Cylinder

A lock with two keyed cylinders.

Double Cylinder Deadlock

A type of deadlock that requires a key to operate the lock from both sides. The key is needed to retract the bolt, making it more secure but also potentially dangerous in emergency situations.

Driver (driver pin)

Any pin in a pin stack that sits adjacent to a spring.

Dual custody

Dual custody refers to a security measure where two or more people are required to work together to gain access to a secured area or to perform a critical task.

Double locking

A feature in locks that requires the use of two separate mechanisms to unlock it.

Drilled-through spindle

A spindle that has a hole drilled through it to allow a cotter pin or set screw to secure it.

Ear of key or shoulder

The portion of the key that protrudes from the bow and engages with the lock’s internal components.

False gate

A cut in a pin tumbler that is shallower than the true gate, designed to mislead picking attempts.


A flat plate attached to the front of a lock, covering the lock body and concealing the bolt mechanism.

False Set

A partial rotation of a pin tumbler as a result of applying tension to the plug.

Full rebated

A lock designed to fit within a recess in a door, with a flat face and no projecting parts.

Full-width pad bar

A locking bar that spans the full width of a door, providing additional security against forced entry.

Grand master key

A key that can operate all locks within a group or system, including those operated by individual master keys.

Great grand master key

A key that can operate all locks within multiple groups or systems, including those operated by grand master keys.


A channel or cut in a key blade or lock component to allow for the insertion and movement of other components.


Removable plates or covers used to protect locks from drilling, picking, or other attacks.


A type of bronze alloy used for casting locks and other hardware.

Hard Plate

A hardened steel plate inserted to protect a lock from drilling or punching attacks.


A hinged metal plate with a loop used to secure a door or lid with a padlock.

Heel & Toe Locking

A mechanism where both ends of a shackle lock into the padlock body, providing extra security.

Heel (of a padlock shackle)

The end of a padlock shackle opposite to the lock body.

Hollow Post Key

A key with a hollow cylindrical shaft, designed to fit over a corresponding post in a lock.

Hook Bolt

A type of locking bolt with a curved end that hooks into a strike plate or keeper.


A technique for making a working key by filing a blank to match the marks left on it by a lock’s pins.

Interconnected Lockset

A lockset with a deadbolt and latch operated by a single lever or knob.


The vertical side of a door or window frame where a locking bolt or latch enters.

Key Pins

The pins in a lock that are raised or lowered by the key to align with the shear line and allow the lock to turn.


The slot in a lock cylinder that accepts the key.

Lock Housing

The outer casing of a lock that encases the internal components.

Lock Cylinder

The portion of a lock where the key is inserted and turned to operate the lock.


A mechanism used to hold a door or window in place.


A complete door-locking system that includes a latch and a lock.

Lever Handle

A handle used to operate a lock, typically found on lever locks.

Lever Lock

A type of lock that uses a set of levers to prevent the bolt from moving in the lock housing.

Lever Mechanism

The set of levers inside a lever lock that must be properly aligned to allow the bolt to move.

Lever Pack

The set of levers inside a lever lock that is lifted by the key to align with the shear line.

Lever Pivot

The point where the lever rotates within the lock mechanism.

Lever Tumbler

A component inside a lever lock interacts with the key to move the levers.

Link Plate

A metal plate that connects the lock body to the locking mechanism.


The protruding edge of a lock or latch that is mounted to a door or frame.


A device that is used to secure a door, window, or other objects to prevent unauthorized access.

Lockable Bolt

A bolt that can be locked in place to secure a door or window.

Locking latch

A latch with a built-in lock mechanism, usually operated by a key or combination.


A complete locking system that includes a lock, latch or deadbolt, strike plate, and all necessary hardware.


A professional who specializes in locks and security systems, including installation, repair, and maintenance.

London strip

A method of forced entry that involves cutting a slot into the door frame to manipulate the latch or lock mechanism.

Long shackle

A padlock with a longer-than-average shackle for use in applications with larger clearances.

Lower pins

The set of pins in a lock cylinder that interact with the key cuts to control the rotation of the core.


The process of applying a substance, such as oil or graphite, to the moving parts of a lock to reduce friction and extend its lifespan.

Master pin

A specially sized pin in a lock cylinder that creates a shear line at a specific location, allowing multiple keys to operate the lock.

Master Key

A key that can open multiple locks in a system, while each lock also has its own individual key.


A type of lock or latch that is installed within a recess at the edge of a door.

Narrow case lock

A type of lock that is designed for installation in narrow door frames or other tight spaces.


A type of lock that automatically latches when a door is closed, and can only be opened with a key or thumb turn from the inside.


A small metal tube that is used to apply lubricant or other substances to the interior of a lock cylinder.


A technique in lock picking where the driver pins are lifted too high above the shear line.


A tool used to manipulate the pins or discs inside a lock to open it.

Pick Gun

A tool that uses a rapid series of striking motions to set pins in a lock.

Pin Tumbler Lock

A lock that uses a set of pins that must be aligned at the shear line to allow the lock to turn.


The process of selecting and inserting the correct pins in a lock cylinder to match a specific key.


A tool used in lock picking to rapidly move the pins up and down to set them.

Rack bolt

A type of lock bolt that slides horizontally often used on sliding doors.

Radiused forend

A door edge plate that has a curved, rather than square, corner.


A step or recess on the edge of a door or frame to accommodate the lock mechanism.


A lock that is designed to fit into a recess in a door or frame.

Tension Wrench

A tool used in lock picking to apply torque to the lock cylinder, allowing the pins to be manipulated.


The mechanism that allows a locked door or window to be opened from the inside.


A security device that prevents a safe from being opened if the lock is tampered with.

Set Pin

A pin in a lock cylinder that is lifted to the correct height to align with the shear line, allowing the lock to be opened.

Shear Line

The separation point between the inner and outer cylinder of a lock, which allows the plug to rotate and the lock to be opened.

Single Pin Picking

A lockpicking technique that involves lifting and setting each pin in a lock individually.


A latch or lock mechanism that can be operated with a thumb turn or knob.

Tension Wrench

A tool used in lockpicking to apply tension to the lock cylinder while manipulating the pins.

Torsion Bar

A type of lock pick used to rotate the plug of a lock, allowing it to be opened.


A locking mechanism consisting of a series of pins or discs that must be aligned in order to open the lock.


Obstructions within a lock cylinder that prevent a key from being inserted or turned without the correct key profile.


A type of locking mechanism used in some cylinder locks, consisting of flat, spring-loaded wafers that align with the key cuts to allow the lock to be opened.

Wafer Tumbler Lock

A type of lock that uses flat, wafer-shaped tumblers that are arranged vertically in the keyway. The tumblers align at the shear line when the correct key is inserted, allowing the lock to be turned.

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