The locksmith glossary.
68 terms explained in plain English, with links to the lessons where they become useful.
17 terms
Explore the lesson ↗Mechanical fundamentals
- Backset
- The distance from the door edge to the reference centerline specified for the lock preparation. Match the hardware drawing rather than assuming every door uses the same dimension.
- Bitting
- The pattern of cuts that makes a mechanical key operate its intended lock. It is different from the keyway profile that determines which blank can enter the cylinder.
- Bore
- A prepared hole in a door for hardware. A cross bore goes through the door faces; an edge bore enters from the door edge.
- Cylinder
- The key-operated component of a lock. A replaceable cylinder and the complete lockset are different parts of an opening.
- Deadbolt
- A bolt that is positively extended and retracted by its operating mechanism rather than pushed back by contact with the strike in normal use.
- Door handing
- A description of the door swing and the side used as the reference. Manufacturers may use different conventions, so record the viewpoint and consult the product diagram.
- Key blank
- An uncut or unfinished key made with a particular profile and dimensions. Blank selection precedes cutting.
- Keyway
- The shaped passage into which a key enters a cylinder. A matching-looking key head does not establish a matching keyway.
- Latchbolt
- A usually spring-loaded bolt that holds a door closed by engaging a strike. Its operation differs from that of a deadbolt.
- Mortise lock
- A lock whose body fits into a pocket prepared in the edge of the door. It is not interchangeable with a bored lock merely because the trim looks similar.
- Pin stack
- A set of interacting pin components in a pin-tumbler cylinder. The intended key positions those components so the plug can rotate as designed.
- Plug
- The part of a cylinder that receives the key and rotates when the locking mechanism permits it.
- Rekeying
- Changing a compatible cylinder’s internal keying to operate with a different key. It does not by itself repair a worn lock or misaligned door.
- Shear line
- In a conventional pin-tumbler cylinder, the interface between the plug and surrounding shell. Correct pin alignment permits intended rotation at that interface.
- Strike
- The receiving hardware on the frame for a latch or bolt. Its position and compatibility affect the operation of the opening.
- Tailpiece
- A component that transfers motion from a cylinder to the lock mechanism. Shape, length, and orientation depend on the product.
- Tolerance
- The allowable variation in a dimension or fit. Small differences can matter even when parts appear identical to the eye.
16 terms
Explore the lesson ↗Automotive keys
- Add-key task
- Enrolling an additional supported key when the vehicle meets the relevant prerequisites. The required existing-key situation varies by system.
- All keys lost
- A job category in which no working key is available. It is not simply an add-key job with an empty customer keyring; preparation and procedures may differ.
- Blade
- The mechanical part of a vehicle key. Correct cutting does not establish electronic compatibility or start authorization.
- Cloning
- Creating a supported transponder credential that reproduces an existing credential’s identity. This differs from enrolling a separate identity in a vehicle.
- Emergency blade
- A mechanical blade included with some fobs for the vehicle’s specified backup access method. Its presence does not make every fob electronically compatible.
- FCC ID
- An identifier associated with radio-equipment authorization in the United States. It is useful identification evidence, not a complete vehicle-fitment guarantee.
- Fob
- A handheld housing containing key or remote functions. Two identical housings can contain different electronics.
- Immobilizer
- A vehicle security function that restricts starting or operation until the required authorization is recognized. A no-start symptom does not alone prove an immobilizer fault.
- Key enrollment
- The process of establishing a supported key’s electronic relationship with the vehicle system under the applicable procedure.
- OBD connection
- A connection through the vehicle’s diagnostic interface. Having a physical connection does not mean a tool supports every module or security function.
- OEM
- Original equipment manufacturer. In parts research, distinguish the original manufacturer’s identifier from a seller’s stock number or cross-reference.
- Onboard programming
- A supported learning or enrollment procedure provided through the vehicle itself. Availability and prerequisites must be checked for the exact application.
- Proximity key
- A credential used for supported passive entry or starting functions. Backup operation and electronic architecture are vehicle-specific.
- RKE
- Remote keyless entry. Button-operated locking functions should be distinguished from start authorization and passive-entry functions.
- Transponder
- An electronic component that responds to a compatible system. In vehicle keys, it participates in the relevant authentication process.
- VIN
- Vehicle identification number. Use it with the relevant parts and service information; do not assume a VIN alone answers every equipment or fitment question.
12 terms
Explore the lesson ↗Electronics and diagnosis
- Battery support
- Equipment used to maintain the electrical conditions specified for a service procedure. The required capability and settings come from the vehicle and equipment instructions.
- Continuity
- An indication of an electrical path under the meter’s test conditions. A continuity beep alone does not prove that a circuit will perform correctly under load.
- Current
- The rate of electric charge flow, measured in amperes. Measuring current uses a different circuit arrangement from measuring voltage.
- Diagnostic trouble code
- A recorded condition detected by a control system. A code supports a diagnostic investigation; it is not automatically a command to replace a named part.
- Ground or reference
- A reference point used for an electrical measurement or circuit. Record which reference was used when comparing measurements.
- Open circuit
- An interruption in the intended current path. The location and cause need to be established through an appropriate diagnostic method.
- Resistance
- Opposition to electric current, measured in ohms. Resistance testing requires the conditions specified by the meter and component instructions.
- Service information
- The applicable manufacturer instructions, diagrams, specifications, and diagnostic procedures. It should match the exact system being serviced.
- Short circuit
- An unintended electrical path. Its effect depends on where that path occurs; it should not be used as a vague label for every electrical fault.
- State of charge
- An estimate of how much charge remains in a battery. It is different from the battery’s overall condition or ability to supply a particular load.
- Voltage
- Electrical potential difference between two points, measured in volts. Record the measurement points and operating conditions with the reading.
- Voltage drop
- The difference in electrical potential across part of a circuit under stated conditions. The circuit’s load state matters when interpreting the result.
14 terms
Explore the lesson ↗Commercial access
- Access group
- A defined set of people or credentials assigned particular permissions. A well-designed group follows an actual role rather than simply copying another person’s access.
- Audit trail
- A record of system events. A recorded credential event and physical confirmation that a person entered are not always the same thing.
- Closer
- Hardware that controls the closing movement of a door. A closer, latch, and door alignment must function together.
- Credential
- Evidence presented to an access-control system, such as a card or mobile credential. The reader obtains information; the system applies the access decision.
- Door contact
- A sensor that reports a door’s monitored position. Its indication does not necessarily verify that a latch has fully engaged.
- Egress
- Movement out of a space. An opening’s exit requirements are distinct from the question of who may enter from the outside.
- Electric strike
- An electrically controlled component at the frame that works with compatible latch hardware. Suitability depends on the complete opening and application.
- Exit device
- Door hardware operated through an actuating member for exit. Product listing, function, and the opening’s requirements determine the appropriate use.
- Fail safe
- A power-loss condition in which the relevant electrically controlled locking function releases. This term alone does not describe every aspect of exit or fire-door compliance.
- Fail secure
- A power-loss condition in which the relevant electrically controlled locking function remains secured. Mechanical egress must be evaluated separately.
- Key control
- The administrative and physical practices used to manage key creation, issue, return, storage, and change authorization.
- Master key
- A key that operates a group of master-keyed cylinders that also accept their respective change keys. This is different from simply keying several cylinders alike.
- Reader
- The component that receives information from a presented credential. In a typical system, the access decision belongs to the controller or system logic.
- Request to exit
- An input or event used by an access system to recognize an exit request. Its purpose and relation to unlocking depend on the designed system.
9 terms
Explore the lesson ↗Training and professional practice
- Accreditation
- Recognition of an organization or program under a particular accrediting body’s standards. It is different from a student’s course completion certificate.
- Apprenticeship
- A structured way of learning through work and instruction. A formally registered apprenticeship and an informal trainee job are not automatically equivalent.
- Authorization
- Permission from the appropriate party for a defined scope of work. A person’s possession of a key is not, by itself, a complete authorization record.
- Certification
- A credential awarded under an issuing organization’s requirements. Check what was assessed and whether that credential is relevant to the intended role.
- Competency
- An ability that can be demonstrated against stated criteria. Reading, observing, and performing with supervision are different stages of development.
- Estimate
- A description of expected work and cost based on stated information and assumptions. Clarify what would require revised approval.
- License
- Government permission to perform a regulated activity under the applicable rules. Requirements can differ by location and by employee or business role.
- Scope of work
- The agreed task, intended outcome, and boundaries of a job. It provides a basis for preparation, approval of changes, and completion checks.
- Work order
- A record connecting the customer’s request, authorization, agreed work, results, and handover. Store sensitive information through the business’s approved process.
Use the term, then check the application.
A definition gives you a shared starting point. It does not identify a specific lock function, establish a vehicle part match, or replace a product specification. When a term changes a purchasing or installation decision, use the exact manufacturer drawing or service information.
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