Jargon Buster

Butt Hinges:

Butt Hinges: A type of hinge commonly used to assemble doors.


Caming: Formed metal stripping, usually made of brass or zinc plated steel, used between cut-glass pieces to assemble the pieces into a decorative glass panel. Caming is soldered at joints to bond the glass assembly together.


Core: The centre section of a door.


A latch used to secure a door closed, the latch being driven from the door into a receiver in the jamb or frame.


Doors that have two layers of glass with a sealed airspace between to help keep a building warm and to reduce noise from outside of a property.


Dowelled: A method of door construction using dowels to connect the different part of a door together.


Engineered: Doors made up of timbers that have been constructed from small pieces of timber, glued together, and then over veneered.


A stamped decorative plate, usually circular to trim the shaft of a door knob or deadbolt latch, to trim the opening where the shaft or latch adjoins the face of a door.

Etched Glass:

Etched Glass: Glass used for doors on which a decorative pattern is engraved by means of chemical action or mechanical sand-blasting.


The plated or solid metal trim piece, usually about 1 x 2-1/4 inches, housed flush into the edge of a door, through which projects the latch of a passage lock or deadbolt.

Fire Door:

A door of a construction type which has been tested to contain the spread of fire from one room or occupancy area to another. Fire doors are listed and labelled to show their ratings in terms of time, i.e. 60 minutes etc...


A term which describes or determines the direction of swing of a door when opening.


An assembly of metal plates and a cylindrical metal pin, which when fastened to a door edge and to a door frame, allows the door to swing or rotate in its frame.

Intumescent Strip

An intumescent strip is a component for a Fire Door. It is placed around the door frame and is chemically designed to automatically expand when exposed to extreme heat, thus sealing the gap around the frame. This therefore contains the fire and allowing for enough time to escape. This is very important as isolates the fire to one particular area and helps to protect people whilst also minimises damage to the building itself. It differs from a smoke seal as that is used to block smoke and not contain a fire. We offer a range of options for our internal fire doorkits.


A vertical perimeter frame part of a door system.


A moveable, usually spring-loaded pin or bolt, which is part of a lock mechanism, and engages a socket or clip on a door jamb, retaining the door closed.


Lipping: Timber material that is used on the outside of a door. Enables a door to be altered in size without disturbing its core.

Lock Block:

A rectangular block of wood or other solid material, placed inside a door assembly at the lock side edge, which reinforces the assembly when the lock hardware is installed.

Low-E Glass:

Glass which has been factory coated with a thin layer of material, nearly clear, which acts to absorb and reflect heat and light energy.

Mortice & Tenon (M&T):

Mortice & Tenon (M&T): Method of joint construction. Traditionally how an external door was constructed.


Mullion: A post or divider which runs from sill to frame top in a multi-panel door, door, or door and side light assembly.


A rectangular recess cut or formed along the long edge of a part, usually a wood part.

Safety Glass:

Glass which when broken, shatters into small pieces without sharp edges.

Side Light:

Side Light: A fixed narrow panel, installed next to a door panel, for decorative purposes. Side Lights almost always contain glass lights.

Smoke Seal

A Smoke Seal is basically a barrier on fire doors that prevent the flow of deadly and hazardous fumes travelling form room to room. It works by being placed between the door frame and the door on all sides. By preventing smoke passing through the gaps between the door and frame, allowing more time to escape as the rest of the building is not affected by heavy smoke. It is important to have a Smoke Seal as inhalation of smoke kills more people than fires do! An is an effective but easy means of preventing this from happening. A smoke seal works differntly from an intumescent strip, as it prevent the smoke spreading whereas a intumescent strip blocks off the fire itself.


Threshold: Another term for sill. The horizontal part of a door assembly, fixed under the door panel and bearing on the floor.


Three layers of glass with a sealed airspace between the outer and inner sections help keep a building warm and to reduce noise from outside of a property. Used for more intricate glass designs.


A number which describes in specific terms, the ability of a material or assembly to transmit heat from outside to inside surfaces. Products with lower U-Values transmit less heat than those with higher values.


Veneer: A thin film or facing, adhesively bonded to a core or substrate, which makes up the exposed and decorative face of an assembly.


A permanent curvature or deviation from straightness, which can be induced in a part or assembly by a load or force, or by exposure to heat or moisture.

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