Active Door (in a pair of doors)—The leaf that opens first and the one to which the lock is applied.

Auxiliary Dead Latch —A supplementary latch that automatically deadlocks the main latch bolt when the door is closed. (Also called Deadlocking Latch Bolt)

Backset (of a lock)—The horizontal distance from the face of the lock to the center line of knob hub keyhole or cylinder. (Measured from the high side of a beveled door.)

Backset (of a hinge)—The distance from the edge of the door to the hinge.

Chain Door Fastener—A device that limits the opening of a door by means of a chain.

Deadbolts—A lock bolt having no spring action nor bevel, and which is operated by a key or a turn piece.

Door Stop—A device to stop the swing or movement of a door at a certain point. Also an architectural term defining that part of a door frame against which the door closes.

Double-Throw Bolt—A bolt that can be projected beyond its first position into a second, or fully extended one, thus providing extra security.

Drop Escutcheon (or Key Plate)—One having a pivoted plate that covers the keyhole.

Edge Plate—An angle or channel-shaped guard used to protect the edge of a door.

Edge Pull—A pull mortised into the edge of a sliding door.

Entry Sets—A door system consisting of a separate handle to open latch and a keyed deadbolt lock.

Fittings—Various hardware pieces used to fit and custom fit other hardware pieces and thus allow proper and secure installation of hardware units. All necessary fittings come with hardware unit and custom fittings are available separately.

Grand Master Key—A key that operates locks in several groups, each of which has its own master key

Hardware—Term applied to all hardware used in building construction but particularly that used on or in connection with doors, windows, cabinets and other movable members.

Inactive Door (or leaf)—That leaf of a pair of doors that does not contain a lock, but is bolted when closed, and to which the strike is fastened to receive the latch or bolt of the active door.

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

Knob—A projecting handle of various sizes and styles for operating a latch/lock.

Lever—A horizontal handle for operating the latch/bolt(s) of a door/lock.

Master Key—Operates any quantity of cylinders of different individual key changes.

Masterkeying—An arrangement of cylinders having individual key changes, which permits them all to be operated by a simple key called a master key

Pull—A cabinet handle style which is designed for increased and  more comfortable grip surface while opening cabinetry.

Push Plate—A plate applied to the lock stile to protect the door against soiling and wear.

Rail (of a door)—A horizontal member that joins the stiles. May be exposed as in a paneled door, or concealed as in a flush door.

Rose—A trim plate attached to the door under the knob. It sometimes acts as a knob bearing.

Sideplates—A lock that consists of two plates: the under plate is fastened to the case and is unfinished; the finish plate is fastened to the under plate and when in place covers the cylinder set screws, thus protecting them from tampering. Used on mortise locks.

Side Knob Screw—A set screw used to fasten a knob to a spindle.

Spindle (of a knob)—The bar or tube connected with the knob or lever handle that passes through the hub of the lock or otherwise engages the mechanism to transmit the knob action to the bolt(s).

Stile (of a door)—A vertical member of the door structure; each door has two: a lock stile and a hinge stile.

Strike—A metal plate or box that is pierced or recessed to receive the bolt or latch when projected. Sometimes called Keeper.

T Hinge—A surface hinge with the short member attached to the jamb and the long member attached to the door.

Template Hardware—A term indicating any item of hardware that is made to template; that is, exactly matching the master template drawing as to spacing of all holes and dimensions.

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

Throw (of a deadbolt or latch bolt)—Measurement of the maximum projection when bolt is fully extended.

Thumb Piece (of a handle)—The small pivoted part above the grip of a handle to be pressed by the thumb to operate a latch bolt.

Tumbler—A guard or obstruction that prevents operation of a bolt except by insertion of the proper key.

Universal—A term used to describe a lock, a door closer or other device that can be used on doors of any hand without change.