Glossary of Locksmith Terms

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Welcome to Millennium Locksmiths’ comprehensive glossary of locksmith terms. As a trusted name in the locksmith industry, we understand the importance of clear communication and knowledge sharing. Whether you’re a loyal customer, a fellow locksmith, or simply someone curious about the world of locks and security, this glossary is designed to provide you with a clear and concise understanding of the terminology we use every day.

At Millennium Locksmiths, we pride ourselves on our expertise and dedication to providing top-notch locksmith services. Our profession encompasses a wide range of skills and knowledge, from traditional mechanical locks to cutting-edge electronic security systems. As the industry evolves, so does the language used to describe the tools, techniques, and concepts that are integral to our work.

At Millennium Locksmiths, we are committed to keeping our customers informed and educated. As the locksmith industry continues to grow and change, we will keep this glossary up-to-date with the latest terminology and advancements in the field. We invite you to explore the terms and descriptions provided here and hope that you find them informative and helpful.




A device used to secure objects, such as doors or containers, by requiring a key or code for access. Locks come in various types, including mechanical, electronic, and smart locks.


A small instrument, usually made of metal, that fits into a lock’s keyway and turns to operate the lock. Keys are cut with specific patterns to match the internal components of a lock.


A type of lock with a bolt that extends into the door frame, providing added security. Deadbolts are operated by turning a key or knob and are often used on exterior doors.


The part of a lock where the key is inserted. It contains pins and tumblers that interact with the key to determine if the lock will open.


A small, movable piece inside a lock that must be aligned properly for the lock to open. Tumblers are part of the lock’s internal mechanism.


Small cylindrical pieces inside a lock that interact with the key. When the correct key is inserted, the pins align, allowing the lock to open.

Master Key

A key designed to open multiple locks within a master key system. Each lock in the system also has its own unique key, but the master key can open all of them.

Skeleton Key

A key with a simple design that can open many different locks. Skeleton keys are often associated with older locks.


The slot in a lock where the key is inserted. The shape of the keyway corresponds to the shape of the key that fits the lock.

Key Blank

An uncut key that can be shaped to fit a specific lock. Key blanks are used by locksmiths to create duplicate keys.

Key Cutting

The process of shaping a key blank to fit a specific lock. Key cutting is done using specialized machines or tools.


Changing the internal components of a lock so that it operates with a new key. Rekeying is often done when keys are lost or to enhance security.

Lock Picking

The skill of opening a lock without the original key by manipulating its internal components. Locksmiths use lock picking tools to assist with lockouts.

Lock Bumping

A technique used to open a lock by inserting a specially cut key and applying force to “bump” the pins into place. Lock bumping can be used by locksmiths or criminals.


The profession of designing, installing, repairing, and servicing locks and security systems. Locksmiths are skilled technicians who help secure homes, businesses, and vehicles.


A situation where an individual is unable to access a locked space, such as a home, car, or office. Locksmiths provide lockout services to regain access.


A portable lock with a shackle that can be passed through an opening to prevent unauthorized access. Padlocks are commonly used on gates, lockers, and storage units.

Combination Lock

A lock that opens by entering a specific sequence of numbers or symbols. Combination locks are often used on lockers and safes.

Electronic Lock

A lock that operates using electricity. Electronic locks can be controlled by keypads, card readers, or remote devices and offer enhanced security features.

Smart Lock

An electronic lock that can be controlled remotely through a smartphone or other device. Smart locks offer convenience and advanced security options.

Biometric Lock

A lock that uses a person’s unique physical characteristics, such as fingerprints or facial recognition, for access. Biometric locks offer high levels of security.

Mortise Lock

A lock that is installed into a cavity, or mortise, in the edge of a door. Mortise locks are commonly used in commercial and residential settings.

Rim Lock

A lock that is mounted on the surface of a door or gate. Rim locks are often used on older doors or as secondary locks.

Cam Lock

A type of lock used in cabinets and drawers. Cam locks are operated by a rotating cam that secures the lock.

Tubular Lock

A lock with a circular keyway and pins arranged in a circle. Tubular locks are often used on vending machines and bike locks.

Keyless Entry

A system that allows access without a physical key. Keyless entry systems use codes, electronic devices, or biometrics for access.

Access Control

The practice of restricting access to certain areas or information to authorized individuals. Access control systems use locks, codes, and electronic devices to manage access.

Lock Installation

The process of fitting and securing a new lock to a door or other object. Lock installation is done by locksmiths to enhance security.

Lock Repair

The process of fixing a malfunctioning or damaged lock. Lock repair services are provided by locksmiths to restore proper function.

Lock Replacement

The process of removing an old lock and installing a new one. Lock replacement is often done to upgrade security or replace damaged locks.

Lock Upgrade

The process of replacing an existing lock with a more secure or advanced model. Lock upgrades are recommended for enhanced security.

Security System

A set of devices and components used to protect a property from unauthorized access, theft, or damage. Security systems include alarms, cameras, and access control.

Alarm System

A security system that uses sensors to detect unauthorized access and triggers an alarm. Alarm systems are used to deter intruders and alert property owners.


Closed-circuit television, a system that uses cameras to monitor and record activity in a specific area. CCTV is used for surveillance and security.


A secure container used to store valuable items and protect them from theft or damage. Safes come in various sizes and security levels.


A large, secure room or chamber used to store valuable items. Vaults are often found in banks, museums, and government buildings.

Safe Cracking

The skill of opening a safe without the combination or key. Safe cracking is used by locksmiths to assist with lockouts or recover lost combinations.

Safe Repair

The process of fixing a malfunctioning or damaged safe. Safe repair services are provided by locksmiths to restore proper function.

Safe Combination Change

The process of changing the combination of a safe to enhance security. Combination changes are recommended after a safe is accessed by unauthorized individuals.

Car Lockout

A situation where an individual is unable to access their locked vehicle. Automotive locksmiths provide car lockout services to regain access.

Transponder Key

A car key with an embedded electronic chip that communicates with the vehicle’s security system. Transponder keys offer enhanced security against theft.

Key Fob

A small electronic device used to remotely lock and unlock a vehicle. Key fobs offer convenience and security.

Key Programming

The process of coding a transponder key or key fob to work with a specific vehicle. Key programming is done by automotive locksmiths.

Ignition Repair

The process of fixing a malfunctioning or damaged ignition system in a vehicle. Ignition repair services are provided by automotive locksmiths.

Broken Key Extraction

The process of removing a broken key from a lock or ignition. Broken key extraction is done by locksmiths using specialized tools.

High-Security Lock

A lock designed with advanced features to provide enhanced resistance to unauthorized access. High-security locks are recommended for high-risk areas.

Restricted Key

A key that can only be duplicated by authorized individuals or locksmiths. Restricted keys offer enhanced security against unauthorized duplication.

Locksmith Tools

Specialized tools used by locksmiths to perform their work. Locksmith tools include picks, tension wrenches, key cutters, and decoders.

Tension Wrench

A tool used by locksmiths to apply torque to a lock while picking it. Tension wrenches come in various shapes and sizes.

Pick Set

A set of tools used by locksmiths to manipulate the pins inside a lock for picking. Pick sets include various types of picks for different locks.

Bump Key

A specially cut key used to open a lock by bumping the pins into place. Bump keys are used by locksmiths and can also be used by criminals.


A tool used by locksmiths to determine the cuts of a key. Decoders are used for key duplication and lock decoding.

Plug Spinner

A tool used by locksmiths to quickly rotate the plug of a lock after picking. Plug spinners are used to reset locks or open them in the opposite direction.

Key Gauge

A tool used by locksmiths to measure the cuts of a key. Key gauges are used for key duplication and decoding.

Key Impressioning

A technique used by locksmiths to create a key by marking a blank key with the impressions of a lock’s pins. Key impressioning is used to make keys for locks without keys.

Locksmith Certification

A credential awarded to locksmiths who have demonstrated their knowledge and skills through testing. Certification enhances credibility and professionalism.

Locksmith License

A legal authorization required in some areas for individuals to practice locksmithing. Licensing ensures that locksmiths meet certain standards.

Locksmith Code of Ethics

A set of principles and guidelines that locksmiths are expected to follow in their professional conduct. The code of ethics promotes ethical behavior and professionalism.

Locksmith Association

An organization that represents and supports locksmiths. Locksmith associations provide training, certification, and advocacy for the profession.

Emergency Locksmith

A locksmith who provides services outside of regular business hours, often in urgent situations. Emergency locksmiths assist with lockouts, break-ins, and other emergencies.

Residential Locksmith

A locksmith who specializes in providing services for homes and residential properties. Residential locksmiths install, repair, and upgrade locks and security systems.

Commercial Locksmith

A locksmith who specializes in providing services for businesses and commercial properties. Commercial locksmiths secure offices, warehouses, and retail spaces.

Automotive Locksmith

A locksmith who specializes in providing services for vehicles. Automotive locksmiths assist with car lockouts, key replacement, and ignition repair.

Forensic Locksmith

A locksmith who specializes in investigating and analyzing locks and security systems for legal purposes. Forensic locksmiths assist with criminal investigations and legal cases.

Institutional Locksmith

A locksmith who specialises in providing services for institutions such as schools, hospitals, and government buildings. Institutional locksmiths secure large facilities.

Mobile Locksmith

A locksmith who operates from a vehicle and provides services on-site. Mobile locksmiths offer convenience and quick response times.

Key Duplication

The process of creating an exact copy of a key. Key duplication is done by locksmiths using key cutting machines or manual tools.

Key Control

The practice of managing and tracking the distribution and use of keys. Key control systems prevent unauthorized access and enhance security.

Master Key System

A system that allows multiple locks to be operated by a single master key, while each lock also has its own unique key. Master key systems are used in large facilities.

Keyed Alike

Locks that are designed to be operated by the same key. Keyed alike locks offer convenience for users with multiple locks.

Keyed Different

Locks that are designed to be operated by different keys. Keyed different locks offer enhanced security against unauthorized access.

Anti-Pick Lock

A lock designed to resist picking attempts. Anti-pick locks have features that make it difficult to manipulate their internal components.

Anti-Drill Lock

A lock designed to resist drilling attempts. Anti-drill locks have hardened components that make it difficult to drill through them.

Anti-Bump Lock

A lock designed to resist bumping attempts. Anti-bump locks have features that prevent the pins from being bumped into place.

Anti-Snap Lock

A lock designed to resist snapping attempts. Anti-snap locks have features that prevent the lock from being broken or snapped.

Door Reinforcement

The process of strengthening a door and its frame to enhance security. Door reinforcement includes adding strike plates, deadbolts, and other hardware.

Strike Plate

A metal plate attached to a door frame that receives the latch or bolt of a lock. Strike plates enhance the security of a door by providing a strong point for the latch or bolt to engage.


A mechanism that holds a door closed by extending into a strike plate. Latches are commonly used on interior doors and are operated by turning a knob or handle.


A metal rod that extends from a lock into a strike plate to secure a door. Bolts are used in deadbolts and offer a higher level of security than latches.


A hinged metal plate used with a padlock to secure a door or container. Hasps are commonly used on gates, sheds, and storage units.

Chain Lock

A lock that uses a chain to secure a door, allowing it to be partially opened for viewing or communication. Chain locks are often used on apartment doors for added security.

Door Viewer

A small optical device installed in a door that allows the occupant to see outside without opening the door. Door viewers enhance security by allowing residents to verify the identity of visitors.

Door Closer

A device that automatically closes a door after it has been opened. Door closers are commonly used in commercial buildings to ensure that doors remain closed.

Panic Bar

A horizontal bar on a door that allows it to be quickly opened from the inside in an emergency. Panic bars are required on exit doors in many commercial buildings.

Exit Device

A device that allows a door to be easily opened from the inside, often used in commercial buildings. Exit devices include panic bars and push bars.

Push Button Lock

A lock that uses buttons to enter a combination for access. Push button locks are commonly used on doors and safes.

Card Reader

A device that reads information from a card, often used for access control. Card readers are used in hotels, offices, and other secure areas.

Keypad Lock

A lock that uses a keypad to enter a code for access. Keypad locks offer convenience and security without the need for a physical key.

Fingerprint Lock

A lock that uses a person’s fingerprint for access. Fingerprint locks offer high levels of security and convenience.

Retractable Bolt

A bolt that can be extended or retracted by turning a key or knob. Retractable bolts are used in deadbolts and other locking mechanisms.

Locksmith Training

The process of learning the skills and knowledge required to become a locksmith. Locksmith training includes classroom instruction and hands-on practice.

Locksmith Apprenticeship

A program that allows an individual to learn locksmithing by working under the supervision of an experienced locksmith. Apprenticeships provide practical experience and on-the-job training.

Locksmith Insurance

A type of insurance that provides coverage for locksmiths against potential liabilities and risks. Locksmith insurance protects against accidents, injuries, and property damage.

Locksmith Bond

A financial guarantee that a locksmith will perform their work in accordance with laws and regulations. Locksmith bonds protect customers from fraud and misconduct.

Locksmith Regulation

The rules and standards that govern the practice of locksmithing. Locksmith regulations ensure that locksmiths meet certain qualifications and standards of conduct.

Locksmith Standards

The accepted practices and guidelines for locksmithing. Locksmith standards ensure that locksmiths provide quality services and adhere to industry best practices.

Locksmith Best Practices

The recommended methods and techniques for locksmithing. Locksmith best practices promote efficiency, safety, and professionalism.

Locksmith Code of Conduct

A set of guidelines that outline the expected behavior of locksmiths. The locksmith code of conduct promotes ethical behavior and professionalism.

Locksmith Warranty

A guarantee provided by a locksmith that their work will meet certain standards. Locksmith warranties protect customers from defects and poor workmanship.

Locksmith Service Agreement

A contract between a locksmith and a customer that outlines the terms of the services provided. Service agreements specify the scope of work, pricing, and other details.

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