Access Control Electrically or electronically operated system that actuates electric locking hardware to release when a credential such as a PIN code, proximity card or proximity fob is presented to the credential reader.

Active Leaf In a pair of doors, the one that moves, the one that usually moves, or the one that moves first.

Actuator Device that activates an automatic door opener, or power operator.

AHJ Authority Having Jurisdiction. Usually this is the local building inspector or fire marshal.

ANSI American National Standards Institute. Oversees standards and conformity assessment activities in the United States.

ANSI 160 Prep For doors: 2-1/8 inch bore, 7/8 inch crossbore, 2-3/8 inch backset; for door frames: “T” or “D” strike, or ASA strike.

ANSI 161 Prep For doors: 2-1/8 inch bore, 1 inch crossbore, 2-3/4 inch backset: for door frames: ASA strike.

ANSI 86 Prep For doors: door prepared with mortise pocket, for mortise locks with faceplate (or lock front) size 8 inches by 1-1/4 inches; for door frames.

ASA Strike Lock strike for ANSI 161 or 86 prep, 4-7/8 inches tall by 1-1/4 inches wide with 1-3/16 inch lip. Optional strike for ANSI 160 prep.

Astragal On a pair of doors, a flat metal strip that is attached to one leaf and extends slightly over the edge of the other leaf. Used for security and/or weatherproofing.

Backset Distance from the vertical centerline of the lock to the edge of the door.

Bore Part of the prep for cylindrical locks, the big hole bored straight through the door for the lock chassis. Usually 2-1/8 inches in diameter.

Centerline Imaginary line that marks the middle of an object.

Construction Core Interchangeable core for use during the construction phase of a project. Construction cores are keyed alike and have a common control key. Keys are usually sold separately. Construction cores are thrown away or returned after the construction phase and replaced by permanent cores.

Construction Key Key used during the construction phase of a project.

Construction Keyed Condition of a key cylinder in which it is keyed alike for use during the construction phase of a project. Some construction keyed cylinders are prepared for field transformation to permanent keyed cylinder. Lost ball and split key construction keying are two examples.

Construction Master Key see construction keyed

Control Key Key used to insert or remove an interchangeable core.

Credential Set of numbers entered into a keypad, or proximity card, magnetic stripe card, or other object, that is recognized by an access control system. The access control system uses the information provided by the credential.

Crossbore Part of the prep for cylindrical lock, hole drilled from the edge of the door through to the bore for the latch. The centerline of the crossbore is the same as the centerline of the bore.

CVR Concealed vertical rod exit device. No surface-mounted rods, mullions or metal wraps are visible. Hardware is contained in the interior of the door.

Cylinder Also, key cylinder. Part of a lock that is operated by a key.

Cylinder Dogging Exit device latch holdback feature actuated by a key cylinder.

Degree of Opening Angle marking the furthest point to which a door can be opened. For example, some overhead door holders allow a 110-degree opening.

Delayed Egress System whereby egress is delayed (typically) 15 seconds; system is activated by applying pressure to exit device or door, or alternatively by pushbutton if allowed by AHJ.

Dogging Latch holdback feature found on many non-fire rated exit devices.

Door Closer Mechanism that automatically closes a door; usually hydraulic, spring-driven mechanism.

Door Schedule Document containing descriptions, illustrations and dimensions of the doors that will be use for each opening.

Door Stop Object intended to limit the degree of swing. Commercial door stops are typically applied to the floor in the arc of the swing of the door, or on the wall. Usually installed to prohibit the door or lock from striking the wall.

Door Swing Arc created by the motion of a hinged door.

Double Acting Door A door that swings both in and out.

Double Egress Door Two doors placed in the same opening. One door swings in and the other swings out.

DPDT Double Pole, Double Throw. Electric switch that consists of the two sets of SPDT terminals or leads.

Egress Door Opening that is in the path of egress.

Electric Latch Retraction Feature that pulls the latch back to an unlatched position using electricity, either via solenoid or by electric motor. Used commonly with exit devices and less commonly with mortise locks.

Electric Strike Electrically operated mechanism installed on the door frame for the purpose of releasing the latch of a locking mechanism remotely or by access control.

Exit Device Locking mechanism for out swinging doors that has an activating push bar that is at least half the width of the door on which it is installed, allowing single motion egress with no prior knowledge required.

Extended Lip Applies to strikes. Extended lips have longer-than-standard lips to allow for moldings applied to the surface of the door frame or casing. The extended lip prevents damage to the molding.

Fail Safe When no power is applied the door is unlocked.

Fail Secure When no power is applied the door is locked.

Finish The color of the hardware.

Fire Door Door that is rated by Underwriters Laboratories as one that will remain closed and function for a certain period of time while simultaneously on fire and blasted with high pressure water.

Fire Rated Applies to door and door hardware. The term means that the object described complies to the Underwriters Laboratories specifications for fire rated doors and door hardware. Fire rated doors and door hardware are usually labeled as such.

Form "C" Relay Electrical relay consisting of common, normally open and normally closing wiring terminals or lead, also called Single Pole, Double Throw, or SPDT.

Frame Also, door frame. Usually rectangular construct made of three members consisting of two vertical "legs" connected by a cross member at the top that is called the "header".

Grand Master Key Key at or near the top of the key hierarchy within a master key system, which means that it opens most or all of the locks within the system.

Handing Describes the direction a door swings relative to the hinge pin. For help determining handing, click here.

Header Horizontal top member of a door frame.

Inactive Leaf In a pair of doors, the one that does not move, moves less often, or moves after the active leaf.

Interchangeable Core Key cylinder that can be installed or removed by a control key.

Interconnected Lock Lock that combines a cylindrical lever and deadbolt into one unit. Turning the interior lever retracts both the latch and the deadbolt.

Keyed Alike Ref. locks: the state of being operated by the same key. Not the same as master key.

Key System System that determines which key fits a lock or group of locks within the system.

Labeled Door A fire-rated door.

Lead Lined A sheet of lead applied to a lock rose or case. Usually on X-ray room doors.

Leaf One of a pair of doors.

Leg Vertical member of a door frame.

LFIC Large Format Interchangeable Core (FSIC by Allegion).

Lite A window that is installed in the body of a door or elsewhere in an opening (transom, side lite).

Lite Kit Kit that allows installation of a window into an existing door.

Lock Front Metal plate on the edge of the door through which the lock latch or bolt extends.

Lock Stile Vertical member of the door where the lock will be installed.

Master Key A key that opens multiple locks that may also have their own individual keys within a key system.

Master Keyed Condition of a key cylinder wherein a cylinder can be operated by a master key in addition to the individual (operating) key assigned to a cylinder or group of cylinders.

MK ref. cylinder, master keyed

MKKD ref. cylinder, master keyed, keyed differently

Molex Connector Plug-in connectors for electrical applications made by the Molex company.

Mullion (1.) Horizontal member of a door, located somewhere between the top and the bottom. (2.) Vertical member placed in the middle of a pair of doors.

Opening Rectangular hole in a wall in which doors are installed.

Overhead Stop/Holder Mechanism applied to the door and door header to limit door swing and/or hold the door open.

Pair of Doors Two doors placed in the same opening. One door is left-handed and one is right-handed. Also called "double doors".

Panic Threshold Threshold designed to act as the strike for surface vertical rod exit devices.

Patch Fitting Metal piece installed on an all glass door to allow the installation of door hardware. Most require the door to be prepared to receive a patch fitting. This prep work must be done when the door is manufactured. For example, a (usually rectangular) notch is cut in the upper and lower corners of the door on one side for patch fitting hinges.

Path of Egress Route planned by architects for occupants of a building to exit in the event of an emergency, usually marked by lighted exit signs.

Power Operator Electromechanical device that opens and closes doors (single or pairs) when activated.

Rail Horizontal member of a door located across the top or bottom of the door.

Reader Also known as card reader, prox reader, biometric reader, etc. Any device and receives access control credential information and transmits it to the access control controller.

Reveal Underside of the header of a door frame on the push side of a door. Measured from the push side surfaced of the door to the edge of the door frame.

SFIC Small Format Interchangeable Core.

Side Lite Window installed right beside a door, usually full height.

Single Acting Door Door that swings one way.

Split Finish ref: locks, exit devices. One side has one finish (i.e. satin chrome) and the other side has a different finish (i.e. polished brass).

SPDT Single Pole Double Throw. See Form "C" Relay

Stop Raised portion of the inner surface of the rectangle formed by the door frame. Prevents the door from swinging past the frame on single acting doors.

Strike Metal piece installed on the door frame to receive the latch or bolt of a lock.

Strike Box Metal or plastic box installed behind a strike to give a clean look to the recess. Must be ordered specific to the type of strike used.

SVR Surface Vertical Rod Exit Device.

T Strike For cylindrical lock, so named because it resembles the letter T tipped on its side.

Threshold Item fastened to the floor between the legs of a door frame the reduce airflow and/or keep water from passing through the opening.

Transom Area between the header and the celing.

Weatherstripping Hardware and/or gasket applied to the edges of a door or window to limit airflow.