Access control - The means of influencing and regulating the flow of persons through a door (entry and/or exit).
Alternating current (AC) - An electric current that reverses its direction regularly and continually. The voltage alternates its polarity and direction of current flow negative to positive. AC current increases to a peak, decreases through zero, and peaks in the opposite direction. AC current flows back and forth in the conductor and is expressed in cycles per second, or Hertz (Hz). See also Direct current (DC).
Americans with Disabilities Act (ADA) - A US federal law dealing with minimum standards of building accessibility, as well as other issues concerning individuals with disabilities. This landmark legislation provides for stiff civil penalties for any business, workplace, or public institution that fails to provide appropriate access to disabled persons.
American National Standards Institute (ANSI) - A federation of trade, technical, and professional organizations, government agencies.
Ampere (amp) - The unit of measurement for the rate of electrical current flow, characterized by the symbols I (in Ohm's law formulas) or A. One ampere is the current flowing through one ohm of resistance at one volt potential.
Backset - The distance from the edge of the door to the center line of the prep in the door. In the U.S. there are two common backsets for residential door locks, 2-3/8" and 2-3/4". Dummy sets have no latch and are surface mounted so you can install a dummy set wherever you choose on the door.
Builder’s Hardware Manufacturers Association (BHMA) - the trade association for North American manufacturers of commercial builders hardware
Bolt - The projectable member of a lock or latch mechanism that engages the door frame and the strike. (See deadbolt and latchbolt.)
Cable - A group of insulated conductors in a common jacket.
Cam - A rotating eccentric piece attached to the end of a cylinder plug to actuate a lock or latch mechanism.
Chassis - The body of the lock itself, without any trim.
Current - The flow of electrons through an electrical conductor. Current is measured in amperes.
Cylinder - The portion of a lock containing the plug with keyway and a body with the pin tumbler mechanism. The properly cut key allows the cylinder to rotate the driver mechanism which unlocks the lock. The two types of cylinders, the mortise cylinder (round, threaded housing) and the bored lock cylinder (sometimes called a cylinder insert), which both provide the same functional value of security and convenience and are often included in the same keying system. (See keying.)
Deadbolt - A bolt operated manually and not actuated by springs. When locked, the bolt cannot be forced back. A deadbolt is operated (projected and retracted) by a key cylinder or lever handle.
Deadlatch - A latch in which the latchbolt is positively held in the projected position by an auxiliary mechanism.
Direct current (DC) - Electrical current that travels in only one direction and has negative (-) and positive (+) polarity. It may or may not have an AC ripple component. DC sources that are unfiltered should be referred to as full-wave or half-wave rectified AC.
Door Closer - A device which automatically controls the closing or position of a door usually via a hydraulic mechanism.
Electric door strike - An electric door locking device (usually solenoid-operated) that will unlock the door when electrical power is applied to it. A fail-safe configuration will operate in the reverse condition (i.e., normally locked when power is applied and unlocked when power is interrupted).
Fail-safe lock - An electric lock that automatically unlocks with any power interruption.
Fail-secure lock - An electric lock that requires power to unlock.
Frequency - The number of complete operations or cycles that take place within a given period of time (normally one second), as in the AC line frequency of 6OHz (61) cycles per second).
Grade of locks - To help identify the quality and durability of locksets and deadbolts, the American National Standards Institute (ANSI) has established three grades or standards for door locks. Each product must pass a series of operational and security tests.
Grade 1 - Meets commercial building requirements. Provides the best residential security available. Grade 1 Knobs = 800,000 cycles, 6 door strikes, 360 pound weight test. Grade 1 Deadbolts = 250,000 cycles, 10 door strikes (hammer test).
Grade 2: Meets light commercial and exceeds residential building requirements. Exceeds standard residential security requirements. Grade 2 Knobs = 400,000 cycles, 4 door strikes, 250 pound weight test. Grade 2 Deadbolts = 150,000 cycles, 5 door strikes (hammer test).
Grade 3 - Meets residential building requirements only. Provides minimal residential security. Grade 3 Knobs = 200,000 cycles, 2 door strikes, 150 pound weight test. Grade 3 Deadbolts = 100,000 cycles, 2 door strikes (hammer test).
Hand (Handing) of door - The description of swinging door operation, always viewed from outside the room, building, and so forth. Left hand means that the door hinges on the left and right hand means that the door hinges on the right.
Keying - The various keying arrangements for pin-tumbler cylinders: individual key – the key for an individual cylinder; keyed alike - all cylinders may be operated by the same key (not to be confused with master keyed); keyed different - a different individual key operates each cylinder (or group of cylinders); master key - a key to operate a group of cylinders, each of which may be set to a different individual key; master keyed - all cylinders in a group can be operated by one master key, although all cylinders may be keyed differently (not to be confused with keyed alike).
Keyway - The channels or grooves in a lock that the key must pass through that distinguish one type of lock cylinder from another. Also called a "Profile".
Keyed Alike - All cylinders may be operated by the same key (not to be confused with Master Keyed).
Key Blank - Uncut keys before they are cut into a working key.
Keyed Different - A different individual key operates each cylinder (or group of cylinders).
Master Keyed - A key to operate a group of cylinder, each of which may be set to a different individual key.
Latch - The locking in of a circuit by means of a holding contact; used in relay logic when a momentary initiation is required.
Latch Protector - A device fastened to the door or frame that prevents access to the latch so it cannot be pried or forced back. Also known as a "Latch Protector", "Latch Guard", or a "Blocker Plate".
Latchbolt - A spring operated bolt with a beveled face to permit a latching action when the door closes.
Lock - A device for securing a door in the closed position against unauthorized or forced entry. It requires actuation to project or to retract its bolt.
Lockset - A locking device, complete with trim, mounting hardware and strike.
Master Keyed - To organize a set of locks typically where each lock opens with it\'s own different key, yet one key will also open all the locks, allowing selective entry to doors to certain users.
Mortise - Pertaining to a method of installation in which only the face plate and trim is exposed. The lock case is installed in a pocket in the door or drawer.
Padlock - A detachable and portable lock with a shackle which locks into its case.
Panic-proof locks - Locks that provide immediate exit from the inside at all times.
Pin Tumbler Mechanism - Small sliding pins in a lock cylinder that work against coil springs. They prevent the cylinder plug from rotating until the appropriate length pin is raised to the proper height by corresponding notch depth cut in the key. Pin tumblers usually consist of bottom pins, top pins and master pins. Most key operated locks provide limited access through the use of pin tumblers.
Rekey - Generally entails disassembling a lock to replace the pins or tumblers inside. Once completed, the lock requires a different key to operate than before.
Rim Exit Device - a mechanical lock applied to the surface of the door that is operated from the inside of an outward swing door through the use of a crossbar or push rail extending at least halfway across the width of the door.
Rim Mounted - A device that is mounted on the surface of the door rather than installed within the door itself.
Rose - A circular trim plate attached to the door under the knob or lever.
Shear Line - The area where the top surface of the plug and the cylinder housing meet. The height which the bottom pins must be raised by the key in order to rotate the key cylinder. Usually a cylindrical shaped tumbler which is often bullet shaped and comes in a variety of lengths that correspond to the depth of the cut of the notch in the key.
Spindle - Bar which connects knobs or levers through the door and operates the lock mechanism. Usually a cylindrical shaped tumbler which is often flat on both ends and is installed directly under a coil spring in the spring stack.
Split Finish - Interior and exterior finishes of are different. Used in coordinating different decor in adjoining rooms.
Springlatch - A plain latch with a beveled latch-bolt that is activated by springs.
Strike - A plate mortised into or mounted on the door jamb to accept and restrain a bolt when the door is closed. In some metal installations of a deadlock, the strike may simply be an opening cut into the jamb. (Synonym: keeper.)
Volt (V) - A unit of electromotive force. It is the difference of potential required to make a current of one ampere flow through a resistance of one ohm.
Voltage - The term most often used (in place of electromotive force, potential, potential difference, or voltage drop) to designate electrical pressure that exists between two points and is capable of producing a flow of current when a closed circuit is connected between the two points.
Watt - The common unit of electrical power. One watt is dissipated by a resistance of one ohm through which one ampere flows.