Definitions of Terms under Alphabet D
Dummy Cylinder

A lock without a latch, typically used for the passive door panel of a double door unit, so that the hardware appears equal to that used on the active panel.

Drywall Opening

A rectangular opening in a wall, usually an interior wall, prepared to the size necessary to receive a pre-hung door assembly.

Drip Strip

In exterior doors, a fitting used across the outside face of the door adjacent to the bottom edge. It is used to divert cascading rain away from the door bottom edge and away from the door/sill joint.


Insulated glass- two panes of glass separated with a sealed airspace between.


Piece of Glass within door, used as a panel(s).

Door Hand

The door hand is the description of which way the door opens.

Deadbolt Spacing

The distance between the cylinder lock to the bore for the deadbolt lock.


A machined or sawn rectangular groove cut into a board or part so that a matching piece can be fitted into it to form a joint.