Dead bolt A bolt which is not actuated by a spring. When locked the bolt cannot be returned by end pressure.
Dead latch A lock containing a deadlatch bolt.
Deadlatch Bolt A spring-actuated bevelled latchbolt which operates in conjunction with an auxiliary boltwhich automatically locks the latchbolt against return by end pressure.
Deadlock A lock incorporating a deadbolt.
Deadlocking Latchbolt A latchbolt which, when the door is closed, can be locked against return by end pressure by operation of a key or turnknob.NOTE: The door cannot be closed after locking the latchbolt therefore this type of lock is not acceptable for fire door sets.
Deadlocking Latch A lock incorporating a deadlockinglatchbolt.
Detainer See Tumbler.
Differs The variation between locks of similar design which allow each lock to be operated only by its own key. ie – keyed to differ
Direct Key Coding A code marked on a key or lock which, with no reference to another series of codes, discloses the key cuts for creating a workable key.
Disc See Tumbler.
Dogging Device See Holdback.
Door Closer (or Door Check) A device attached at the top or bottom of the door, either on the surface or morticed, to regulate and control the operation of the door.
Door Furniture Knobs, levers, handles, roses, plates or escutcheons used in conjunction with locks and latches.
Door Hardware A broad term used to group all the items that are fitted or related to doors, i.e., hinges, locks, padlocks, door closers, pull handles, bolts, stops, tracks, etc.
Door Holder Used for fastening a door in selected open positions.
Door Pull A handle or grip, commonly mounted on a plate, designed for attachment to a door to facilitate opening and closing.
Door Stop A device to limit the opening swing of a door. Also that part of a door frame against which the door closes.
Double Acting Door A door equipped with hardware that permits it to swing to either side of the plane of its frame.
Double-Acting Spring Hinge See Hinge.
Double Bitted Key One having bittings, or cuts, on two sides, to actuate the tumblers of the lock.
Double Egress A pair of doors that are comprised of two single-acting doors swinging in opposite directions, both doors being of the same hand.
Double-Hung Window A window having top and bottom sashes, each capable of movement up and down in its own grooves.
Double Rebate Frame A door frame having two rebates.
Double Throw Bolt A lock bolt that can be extended in stages to increase the bolt projection.
Drawing The process of pulling metal in solid form through dies to after its finish, mechanical properties or cross-sectional shape.
Drip A moulding designed to prevent rainwater from running down the face of a wall, or to protect the bottom of a door or window from leakage.
Drivers The upper pins in a pin tumbler cylinder.
Dry Wall a) A wall finished with wallboard in place of wet plaster or render b) A stone wall built without mortar.
Duct A sheet-metal tube used for air distribution.
Ductile A term used to describe metals soft enough to be stretched, drawn or hammered without breaking.
Dummy Cylinder A cylinder without an operating mechanism, for use where effect is desired.
Dummy Trim A non-operating door trim which is installed for appearance or as a pull handle only.
