Dead Load:
A static applied load. A load without movement.
Door Frame:
The frame into which the door fits, consisting of two upright members called doorjambs, and a door header.
Door Size:
Always specify the width first and the height second: For instance 8' 6″ (2591 mm) wide by 7' 3″ (2210 mm) high. Refer to opening size
Double Thick Glass:
Lighter than plate glass, about 1/8″ (3.18 mm) thick, often termed double strength glass. Refer to glass types
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Drums:
Circular stamped metal parts attached at various locations along the tubular shaft that allows the sheet door curtain to coil up when the door is opened.
End Stiles:
Stile located at each end of a door section that provides for attachment of end hinges.
Escutcheon:
A plate surrounding the lock mechanism, acting as a bearing surface for the lock shaft; one of the parts of a lock set, usually held in place by small screws known as escutcheon screws.
Extension Springs:
Counterbalance springs which provide lifting force by stretching. Commonly called stretch springs. Extension springs are mounted to each of the rear track hangers. They are attached to a pulley at the other end of the spring.
Exterior Lock:
Keyed lock which can be operated on exterior of the door.
Extrusion:
Fabricated aluminum or plastic shapes made by forcing a hot aluminum or plastic billets through a die in an extrusion press.
Flag Bracket:
L-shaped bracket used to facilitate the union between vertical and horizontal tracks.
Flush Design:
Refers to door sections unbroken by roll-formed ribs. The face of the complete door presents an even surface.
Front-Mounted Low Headroom:
Low headroom hardware where springs mount on torsion shaft above opening. (Commercial door application)
Full Vertical Track Assembly:
An assembly made up of a piece of vertical track and a piece of continuous angle or jamb brackets which is used to secure the track to the jamb. (Commercial door application)
Galvanizing:
Zinc coating to protect steel against corrosion.
Glass, Insulated:
Two pieces of glass spaced approximately 1/4″ (12.7 mm) apart and hermetically sealed to form a single-glazed unit with an air space between. Heat transmission through this type of glass may be as low as half that of non-insulated glass.
Glass, Tempered:
Reheated to just below the melting point and suddenly cooled. When shattered it breaks into small pieces. (Commercial door application)
Glass, Wire:
Polished or rough glass, 1/4″ (6.35 mm) thick. Wire mesh is embedded within the glass so that the glass will not shatter when broken. Many types of wire patterns are available. (Commercial door application)
Glazed, Glazing:
Section windows or lights in place of the steel or aluminum panel.
Head Plate:
Structural bracket used to secure vertical and horizontal track, as well as counterbalance systems.
Headroom:
A measurement from the top of the door opening upward to the lowest building obstruction on the inside of the header wall. Use this measurement for vertical clearance all the way back to the end of the horizontal track. (Commercial door application).