Definitions of Terms under Alphabet F

The perimeter to which the door is hinged and latched. See jamb.

Foot Bolt

A steel pin housed in a bottom edge of door or astragal with a latch mechanism, which can be driven down into a receiver socket or hole in the floor or threshold. It allows the door to be better secured when closed.


Rigid foam is used as the insulating and binding core for doors. Flexible foam is sometimes used as a gasket around door openings.


A type of glazed door which has its glass perimeter moldings flush with or set down from the face of the surrounding door.

Fire Door

A door which has been tested to contain the spread of fire from one room or occupancy area to another. Fire doors are listed and labeled to show their ratings in terms of time.

Finger Joint

A way of joining short sections of board stock together, end to end to make longer stock.

Faceplate Mortise

The pocket in the edge of the door that is mortised to the door. Highly secure.


The plated or solid metal trim piece, that is housed flush into the edge of a door.