12 ga., 14 ga., 16 ga, or 18 ga.: Abbreviation for the steel gauge of a frame and/or door.

161 Prep: 2-1/8″ Cutout (or hole) in a door for Bored/Cylindrical locksets.

86 Edge Prep: 8″ Cutout in the edge of a door for mortise lock.


Active Door: The leaf of a pair of doors (double doors), that opens first and has the locking or latching device. The other door is called the inactive door and opens when flush bolts or surface bolts are released.

Astragal: A strip of steel or wood, which covers or closes the gap between the edges of a pair of doors. Some types overlap, others meet at the center line of the gap.

Anchor: A device used to attach a door frame to the surrounding structure or wall.


Backset or B.S. (Lock): The distance from the edge of a door to the center of the hole drilled for a lockset or deadbolt.

Ball Bearing Hinge: A hinge with ball bearings between the hinge knuckles, to reduce friction.

Base Anchor: A piece of metal attached to base of a door frame, to secure frame to the floor.

Beveled Edge: The edge of a door which is not at a 90 degree angle to the face of the door (standard bevel is 1/8 inch in 2 inches)—narrow side of door is side in contact with stop of frame when door is closed.

Borrowed Lite: A four-sided steel frame, which is glazed (has glass) but does not include a door. Often referred to as a steel window frame.

Butt (Hinge): A type of hinge designed for mortising into the edge of a door and into the rabbet of a door frame.


Cam: A rotating piece attached to the end of a cylinder plug to engage the locking mechanism.

Cased Opening: A steel frame with no stops.

Change Key: A key on the lowest level of a master keying system. Change keys are also referred to as day keys. Typically change keys are issued to personnel that require access to one or two areas in a facility.

Closer Reinforcement: A reinforcing piece inside of a door or frame. Provides additional strength for attachment of door closers.

Continuous Hinge: A hinge that extends the full length of a door. Also known as a piano hinge.

Combination Anchor: A device for anchoring a frame to wall constructed with wood or metal stud.

Coordinator: A device used on a pair of doors to ensure that the inactive leaf is permitted to close before the active leaf. Necessary when an overlapping astragal is present and exit devices, automatic or self-latching bolts are used with closers on both door leaves.

Cutout (Door): A piercing for hardware, lite, louvers, and/or accessories.

Cylinder: The cylindrical-shaped assembly containing the tumbler mechanism and the keyway, which can be actuated only by the correct keys.

Cylindrical Lock Prep (161 Prep): Cutout (or hole) in a door for Bored/Cylindrical locksets.


DCDB: Abbreviation for “Door Cut Down Bottom” – Cut door undercut.

Deadbolt: A heavy duty door lock that has no spring action, but is operated by a key or a thumbturn.

Drywall Frame: A three piece door frame, installed after a wall has been erected.

Double Doors: A pair of doors that meet in the middle of the door frame when closed.

Door Closer: A mechanical device that closes a door, in general after someone opens it, or after it was automatically opened.

Dummy Trim: Trim only, without lock. Typically used on the inactive door in a pair of doors or on closet doors with roller latches.

Dutch Door: A door divided into two parts horizontally, allowing one half to be shut and the other left open.


Electric Strike: An electrical device that permits releasing of the door from a remote control.

Existing Wall Anchor (EWA or EOA): An expansion bolt sleeve anchor, used to anchor a frame in an existing block wall. A reinforcement bracket and a punch-out or a punch & dimple prep through the stop of the frame is required for the sleeve anchor to go through. EOA anchors are also used for exterior wood stud walls (new and existing), where the frame butts the wall.

Exit Device: A door-locking device designed to grant instant exit by pressing on a cross bar that releases the locking bolt or latch.


Face (Frame): Exposed part of frame when viewed perpendicular to face of the door also referred to as trim.

FCDB: Abbreviation for “Frame Cut Down Bottom” – Cut jamb legs down in height.

Filler Plate: A blank plate used to fill mortised cutouts.

Fire Lite: A type of ceramic glass used in fire rated doors and frames.

Fire Rated Door or Frame: The ability of a door or frames to provide an effective barrier against the passage of flames, smoke and toxic gases and / or to reduce the transmittance of radiated heat.

Floor Anchor: see base anchor

Flush Bolt: A door bolt mounted (flush) on the inside face or edge of a door. Most often used on the inactive door of a pair of doors.

Flush Door: A door without glass and/or louvers.

Full Glass Door (Design FG): A design of door having glass the entire height and width of the area surrounded by rails and stiles.

Full Louver Door (Design FL): A design of door having louvers the entire height and width of the area surrounded by rails and stiles.

Functions (Lock): A set of operating features for a particular type of lock or exit device which make it suitable for a specific application.

  • Entry / Entrance / Office: Push button locking. Button on inside locks outside lever until unlocked by key or by rotating the inside lever. Inside lever always free.
  • Passage: Latch retracted by levers at all times. Never locked.
  • Privacy: Outside knob/lever locked by pushbutton on inside knob/lever. Rotating inside knob/lever or closing door releases/unlocks button. Emergency release in outside knob/lever.
  • Storeroom / Closet: Outside lever always locked. Latchbolt retracted by key in outside lever or by rotating inside lever. Inside lever always free.
  • Classroom: Outside lever locked/unlocked by key in outside lever. Inside lever always free.
  • Classroom – Intruder: Latch bolt is operated by rotating the inside lever, or rotating the outside lever only when not locked from the inside or outside key. Outside lever is locked and unlocked by turning the key inside or outside lever. Inside lever cannot be locked.

Fusible Link Louver: A louver used in fire-rated doors.


Glazing Bead: Removable trim at a glazed opening to hold glass securely in place.


Half Glass Door (Design HG): A design of door having glass in upper portion only.

Hand (Door Hand): A term used to designate direction in which a door swings. e.g., right hand or left hand

Header (Head): A horizontal frame piece at top of opening or top member of transom frame.

Hinge Jamb: A vertical piece of a door frame prepared for installation of hinges.

Hinge Filler Plate: A plate installed in hinge cutout when hinge is not required.


Inactive Door: A door leaf in a pair of doors which is normally held closed by top and bottom bolts.

Insulated Glass (Double Pane): Glass panes separated by air or gas. The air/gas is trapped between the two pieces of glass and acts as an insulator.

Interchangeable Core (IC): Unlike a standard key cylinder, which is accessible for combinating only via locking device disassembly, an interchangeable mechanism relies upon a specialized “control” key for insertion and extraction of the essential (or “core”) combinating components.


Jamb: A vertical piece of a door frame assembly, adjacent to wall.

Jamb Depth (Frame Profile): The overall width of frame profile—face to face dimension.


Key Side: A reference point used to determine outside of door—sometimes required for handing or determination of secure side of glass bead or louvers.

Keyed Alike (KA): A keying option which allows for any number of cylinders to operate by the same key.

Kick Down Holder: A type of door stop that kicks down to hold the door open; locks in the up position to allow the door to open freely.

Kick Plate: A protective plate applied on the lower rail of the door to prevent the door from being marred.

Knocked Down (KD) Frame: A door frame furnished in three or more parts for assembly in the field.


Laminated Glass: A type of glass that holds together when shattered.

Latch Bolt: A bevel-headed spring bolt that holds a door closed, and is usually operated by a knob or a lever handle

Latch Protector (Latch Guard): A piece of hardware (attached to door) that completely covers the latch area protecting the latch bolt from prying and shimming.

Lite: Preparation in a door for view window, vision and/or glazing including glass stop and glazing bead.

Lite Kit: A complete “door window” kit; includes frame used to hold glass in place, glass and glazing tape.

Long Narrow Lite Door (Design LNL): Design of door with long narrow rectangular lite at lock stile of door.

Louver: An opening in a door with a series of slats or blades to allow passage of air.


Masonry Frame: A frame installed in a new or existing masonry or block opening.

Master Key: A key that opens every one of a given set of locks.

Masterkey System: An arrangement of cylinders having individual key changes, which permits them all to be operated by one key, called a master key.

Mortise: A cavity made to receive a lock or other hardware; also the act of making such a cavity.

Mortise Lock: A lock designed to be installed in a mortise rather than applied to the door’s surface.

Mortise Lock Prep (86 Edge Prep): Cutout in the edge of a door for mortise lock.

Mullion: A fixed or movable post dividing an opening vertically.

Mute: see silencer


Narrow Lite Door (Design NV): Design of door with narrow rectangular lite at lock stile of door.

Non Removable Pin Hinge (NRP): A hinge with a set screw in its barrel; to prevent the removing of hinge pin. Set screw is not accessible when door is closed. Used with outswinging exterior doors.


O.D. Abbreviation for Outside Dimension (refers to outside dimension of door frame)


PACR: Abbreviation for “Parallel Arm Closer Reinforcement” – Welded-in reinforcement, in frame head, for mounting of door closer.

Pair Frame: A door frame, to accommodate two doors or a pair.

Pair of Doors: see double doors

Panic Bar: see exit device

Pocket Door: A door that is prepared to slide into a pocket built in the wall.

Push Plate: A plate applied to the lock stile of a door, to protect against soiling and wear.

PYRAN®: A fire-protection rated and impact safety-rated glazing material made from a transparent glass-ceramic with a thickness of 3/16”


RACR: Abbreviation for “Regular Arm Closer Reinforcement” – Welded-in reinforcement, in frame head, for mounting of door closer.

Rabbet: The recess or offset formed in the frame to receive a door, panel, or glazing.

Removable Mullion: A mullion which can be temporarily taken out of opening to allow the passage of large objects through the opening.

Return: The return leg at the back of frame profile.

Rough Opening: The size of a wall opening into which frame is to be installed.


Self-Closing: When a door must close on it’s own, with the assistance of closing hardware. Properly installed door closers or spring hinges will make a door self-closing. Self-closing doors are required for fire rated openings.

Sidelite Frame: The same as a borrowed lite except that it is attached to door frame.

Silencer: A rubber part attached to the stop on a frame to cushion the closing of a door

Sill (Frame): The bottom horizontal piece of a borrowed lite or sidelite frame.

Soffit: Portion of the frame between stops on a double rabbeted frame and the stop and the largest face on a single rabbeted frame.

Spreader Bar: Metal bars at base of welded frame to keep frame in alignment during assembly, transportation and handling—not to be used for installation.

Steel Stud Anchor: A metal piece inside throat of frame used to secure frame to steel stud.

Sticks: Linear lengths of frame sections used for fabrication of transom/ sidelite frames.

Stile and Rail: A model of door using stiles and rails either mitered or butted— corner joints welded and ground smooth—panel interlocks with stiles and rails and is provided with core or stiffeners—panel may be flush with (flush panel door) or recessed (recessed panel door) from faces of stiles and rails.

Stop (Frame): The part of frame against which door closes.

Strike: A metal plate that is pierced to receive the bolt or latch of a lock, when projected.

Strike Jamb: A vertical piece of a door frame prepared for installation of lock strike.


Tempered Glass: A type of safety glass or toughened glass that has been treated by heat or chemicals to increase its strength. If broken, the glass breaks into small fragments instead of large, jagged pieces.

Threshold: A strip fastened to the floor beneath a door, usually required to cover the joint where two types of floor material meet.

Throat (Frame): The opening between backbends of frame.

Timely Frame: Brand name of a prefinished steel door frame, for stud walls.

Transom Bar: The part of a transom frame which separates the door area portion from the transom area portion.

Transom Frame: A door frame having a panel, louver, sash or glass above door opening with or without transom bar.

Transom Panel: A panel installed in a frame above the door opening.


Undercut: The clearance between bottom of frame and bottom of door—The floor clearance may not be the same as the clearance between the bottom of the door and the finished floor—the floor clearance can only be determined after the finished floor material is in place.


VE: Abbreviation for “Value Engineered” – referring to value engineered door hardware or a value brand.

Vision Lite: A window inside of a door; frame inside of a door used to hold glass in place.


Wire Glass: A type of glass that has a grid or mesh of thin metal wire embedded within the glass.