Glossary of Garage Door Terms


3-Hole Cable Clip
Metal clip tied to end of extension spring cable to allow length adjustment.
Adjusting Cone
(Winding Sleeve, Winding Cone)
Part that fits into torsion spring permitting winding and tension adjustment.
Air Infiltration
The leakage or passage of air through a door system.
Aircraft Cable 7x19
Several strands of thin galvanized wire rope braided together forming 19 strands which are then braided together forming one very flexible cable.
Angle Iron
Length of L-shaped steel material generally used to support and brace rear of horizontal tracks from roof construction or ceiling.
An electrolytic method of coating aluminum with a protective or decorative film, which is generally clear in color.
Weatherstripping added to bottom section of the garage door to seal the opening along the floor.
Back Hangs
The vertical supports for the horizontal track, cross-braced to prevent lateral movement and track spread.
Back Jam/Goal Post
Wood member on the inside surface of the garage, surrounding the door opening.
Horizontal distance measured into a building from the face of the header above a garage door opening to the first obstruction at the required headroom.
Bottom Bracket
A structural support located on the bottom section of the garage door that provides for attachment of the lifting cables on the sectional garage doors. Also referred to as “Bottom Corner Bracket.” (Note: Track rollers may have a separate door attachment in some garage door designs).
Bottom Fixture
A structural support located on the bottom section, which holds the track rollers and provides an attachment for the lifting cables on the sectional door.
Bottom Rail
The lower-most horizontal rail of a door section.
Bottom Weather Seal
Weatherstrip attached to the bottom rail of a door to seal against the floor.
Condition where a garage door bottom rail of a wood door is not level or straight, which is characterized by a closed door “milling” (corners turned up).
Bracket Mounted Track
A method of fastening vertical track to a doorjamb using angle brackets. Also referred to as “Mounted or Track Bracket.”
Breakaway Track
Vertical track assembly that steps back from the jamb used for high lift and vertical lift track to permit outside lock handle projection to clear the lintel (commercial garage door application).
Bumpers, Spring
A leaf spring installed at the end of the horizontal track. Especially useful on lift clearance or full vertical manually operated garage doors, acting as a cushion and stop (commercial garage door application).
Cable Drum
Grooved drum, fitted on torsion spring shaft, onto which lifting cable is wound when door is opened.
Cable Drum Set Screws
Normally refer to set screws that attach the drum to the shaft/tube. One screw may secure the cable to the drum in order to secure proper cable length.
Cable Drums
Grooved drums on the torsion spring shaft that lifting cables wind around when the garage door opens. Designed to allow cable to be accumulated or dispensed in an orderly manner and to prevent lapping or cable chafing.
Multi-strand wire used to attach the garage door, via bottom brackets, to the counterbalance mechanism.
Center Bearing Bracket
A bracket that houses a shaft bearing and aligns and supports the torsion shaft and spring(s) assembly. Also serves to anchor stationary cone(s) to header.
Center Bearing Plate
A plate or bracket that can house a shaft bearing and is used to align and support the counterbalancing mechanism to the torsion shaft as well as anchor one end of torsion springs to the header.
Center Post
The vertical building structure (or member) between two single car doors, or a vertical reinforcement usually installed for high wind events. Sometimes also used to refer to a Vertical Post.
Center Stile/Mutt
Vertical members of a garage door section that provide structural rigidity and location for center hinge attachment (commercial garage door application).
Center Support Bearing
Bearing and mounting plate installed at approximately half the door width above the garage door, which acts as a support for the spring shaft. Can be mounted in various locations, not necessarily in the center, depending on size of the springs.
Chain Hoist
Adds mechanical advantage to manually operated garage doors. Couples to one end of the solid torsion shaft (commercial garage door application).
Chain Hoist Operator
Jackshaft type operator to which chain hoist is attached.
The amount of side room, head room and back room required to properly install a sectional door.
Clevis Pin
A steel pin used in conjunction with a cotter pin to hold a counterbalance cable to a bottom bracket or an operator arm to an operator bracket.
Contour Track
Horizontal track that follows the contour of roof construction or ceiling.
Cotter Pin
A half-round metal strip bent into a pin, whose ends can be flared after insertion through a slot or hole.
Counterbalance System
A system which counteracts the weight of a garage door to allow a reduced force to open and close the door.
A device to connect two counterbalance shafts together, end-to-end.
The part of the sheet door that actually rolls up and down or slides side to side. Manufactured of corrugated sheets seamed together.
One complete cycle of begins with the garage door in the closed position. The door is then opened and closed again. Note: Torsion spring operated garage doors with higher-than-normal cycle life requirements may be specified with 25,000, 50,000, or 100,000 cycle springs.
Door and Access System Manufacturing Association. International manufacturing trade association.
Daylight Opening
Opening dimensions taken between face of jambs and between floor and header.
Dead Load
A static applied load, or a load without movement, generally referring to the weight of the door.
Design Wind Load
Horizontal design load applied to a garage door based on such factors as wind speed, building height and door horizontal location.
Disconnect Chain
Used in conjunction with industrial door operators to disengage operator and permit manual use of emergency hand chain to facilitate operation of door in event of power failure.
Door Closer
A device, combining in one case, a spring to close the door, and a checking arrangement to prevent slamming and to insure silent closing.
Door Frame
The frame into which the door fits; consists of two door jambs, and a door header.
Door Header
The upper part of a door frame, consisting of the head jamb, head casing, stop and trim molding.
Door Jamb
The upright framing on each side of the door opening.
Door Section
A single segment of a sectional door.
Door Size
Door dimensions characterized by the width first and the height second.
Double Door
Commonly used to refer to larger width doors used on two car openings.
Double End Stile
When a door section utilizes two stiles adjacent to each other on each end of the section.
Double Glazing
Use of two thicknesses of glazing within an opening to improve insulating value and/or reduce sound transmission.
Double Top Roller Fixture
Fixture used at the top section consisting of two top brackets to incorporate a longer roller shaft. Usually requires double end stiles on top section.
Drawbar Operator
Electric operator which mounts above the door in the horizontal position and lifts door by pulling and pushing the top section. For normal headroom and low headroom doors.
Drip Lap
An angled Weather Seal provided between sections on steel doors in lieu of a rabbeted joint to prevent entrance of the elements.
Circular stamped metal parts attached at various locations along the tubular shaft that allows the sheet door curtain to coil up when the garage door opens.
Duplex Spring
A combination of two torsion springs of different diameters telescoped within spring fittings.
Electric Opener
Electric motorized device to control door cycling.
Electric Operator
An electrically powered device to control the opening and closing of a door.
Embossed Door Section
Door section featuring embossed panels.
Embossed Panel
Panel containing surfaces raised in relief from a flat surface.
End Bearing Plate
Plate commonly used on torsion spring counterbalance units, which includes a ball bearing to support radial movement of a torsion shaft at each end.
End Stile
Stile located at each end of a door section, which provides for attachment of edge hinges. These stiles carry the total section load and should be of superior strength to provide structural integrity.
Exhaust Ports
Orifices put in the bottom section of a garage door for release of carbon monoxide fumes when tubed from an automobile exhaust system (commercial garage door application).
Extension Springs
Counterbalance springs that provide lifting force by stretching. Commonly called stretch springs. Extension springs are mounted to each of the rear track hangers and attached to a pulley at the other end of the spring.
Exterior Lock
Keyed lock that can be operated on exterior of the garage door.
A metal ring or cap that is affixed to a cable so as to form a bottom or loop on the end of the cable.
Finger Joint
Joint used in joining lumber together at ends of lumber pieces.
Flag Bracket
L-shaped bracket used to facilitate the union between vertical and horizontal tracks.
Flush Design
Refers to garage door sections unbroken by roll-formed ribs. The face of the complete garage door presents an even surface.
Flush Door
Door composed of sections unbroken by visible rails and stiles where the facing of the entire door presents an even surface.
Follow-the-Roof Track
Designed to place the back track on the roof incline, and as close as practical to the roof. Can be used with standard lift or lift clearance track (commercial garage door application).
Full Vertical Track Assembly
An assembly designed from a piece of vertical track and a piece of continuous angle or jamb brackets. Used to secure the track to the jamb (commercial garage door application).
Full Vision Section
A totally glazed section with various types of glass or clear plastic. The section is formed of aluminum extrusions that combine with steel sections above and below.
Zinc coating to protect steel against corrosion.
U.S. Standard, established by congress in 1893, specifying that weight per square foot would be indicated by a numbering system; larger numbers indicate smaller thicknesses and vice versa.
Garage Door Openers.
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 can 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 garage door application).
Insert within a window, designed to give the appearance of divided lights.
Hang Down
The amount of the door that hangs down from the door opening when the door is in the open position.
Header Seal
Weather-stripping which fastens to the top of the door to seal the door along the top of the opening.
Structural bracket used to secure vertical and horizontal track, as well as counterbalance systems.
A measurement from the top of the garage 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.
High Cycle Springs
Special counterbalance springs with increased life cycle capability for high usage garage doors.
High Lift
Distance from header to underside of horizontal track, when high lift track is required.
High Lift Drum
A cable drum contoured to balance a high lift door.
High Lift Track
Track and hardware that causes the door to rise vertically some distance above the top of the door opening before it levels out into a horizontal position.
Hardware item that joins door sections together, and allows sections to pivot independent of each other.
Hoist Electric Operator
Similar to a jackshaft-type operator but with an auxiliary emergency chain hoist in case of a power failure.
Horizontal Radius
Section of track that transitions from vertical to horizontal track welded, bolted or riveted to the horizontal track and then bolted to the flag angle.
Horizontal Rise
The upward slope of the horizontal track which helps to start the door downward and helps maintain cable tension.
Horizontal Track
An assembly usually made up of a section of track and reinforced with an angle that is used to both guide and support the garage door in the horizontal position. Furnished with an integral section of curved track.
Hot Off The Floor
Condition where the door has a tendency to lift off the floor.
International Door Association – dealer/installer trade association.
English unit of measurement of torque.
Inside Hook Up
Connection where the counterbalance cable is on the inside of the track, between the door sections and the vertical track.
Inside Lock
Spring loaded, sliding deadbolt lock operated only from interior of the door.
Insulated Door
Door sections containing insulating material.
Material having ability to reduce heat or cold transmission.
Insulation Terms
BTU Amount of heat necessary to raise the temperature of one pound of water, one degree Fahrenheit. K-value (Thermal Conductivity) Laboratory-determined value of the thermal conductance of a material. R-value (Thermal Resistance) Ability of a material to retard the transmission of heat. The higher the R-value, the better the garage door insulation performance. U-Factor (Heat Transmission Coefficient) Amount of heat, in BTU, transmitted through one square foot of material (the garage door) in one hour at a temperature difference of 1-degree Fahrenheit from one side to the other. The lower the U-value, the better the insulating material.
Acronym for Inch-Pounds Per Turn; torque rate of a spring, indicating the number of inch-pounds of torque delivered to a shaft for each turn the spring is wound.
Jackshaft Opener
Electric operator which mounts on the wall or ceiling and directly drives torsion spring shaft.
Jackshaft-Type Operator
Operator which is mounted on wall or ceiling, with drive provided to turn a torsion shaft.
The upright framing on each side of the door opening.
Jamb Angle (Jamb Bracket)
L-shaped bracket used to fasten vertical tracks to door jambs.
Jamb Seal
Weather-stripping attached to the garage door jamb to provide a seal along the jambs
Joint, Shiplap
A raised back portion of a section joint, fitting with a lowered front portion of a section joint, to create a weather tight seal between door sections.
Joint, Tongue-and-Groove
A joint with an interior raised portion, fitting with a joint with an interior lowered portion, to create a weather tight seal between door sections.
Key Switch Control
Use of key switch to actuate a door operator in place of or in addition to a push-button or transmitter.
Lift Handle
Handle for manually operating a sectional door.
Beam provided over an opening to carry wall and/or roof loads over an opening.
Frames glazed with glass or clear plastic. The number of panels in a section limits the quantity of lites that can be installed. May be double glazed for insulation value.
Long-Stem Roller
Roller with a shaft length of 7 inches or longer.
Low Headroom
Hardware accessories to provide for door installation with minimum headroom conditions. Usually less than 16" headroom.
Low Headroom Track
Special horizontal track with a pair of tracks used to reduce the high point of travel of the top section of a door to permit installation in a low headroom application.
To make a surface smooth or slippery; to reduce friction.
The act of keeping a door system in good working condition.
Acronym for Maximum Inch-Pounds; (IPPT x Turns = MIP); Used to describe the total torque required on a shaft to raise a given door weight from the floor, and also is the measurement of the torque capacity of a particular wire size at a desired cycle level of operation.
A slender dividing bar fixed or removable between two doors. Usually designed to carry wind load and not vertical load.
A bar member supporting and separating panes of glass within a sash or door.
A synthetic rubber made by polymerizing chloroprene.
One-Piece Door
Also known as Shin-busters. A door that operates as one-piece, rather than a door made of multiple sections.
Opener / Operator
A device used to control the up and down motion of a door.
Electric device used to control the up and down motion of the door.
Decorative ornaments of metal, wood or hardboard used for outside decoration of garage door sections.
Padding/Goal Post
Refers to the wood framing at jambs and header to which the garage door track is mounted. Usually furnished by general contractor.
Pan Door
A garage door composed of sheet metal door sections.
The area between stiles in a door section. The “look” of a door is considered the “panel style.”
Pass Door
A swinging pedestrian door built into a sectional door. Not recognized as an exit door by model codes.
Perforated Angle
Angled metal with a serried of punched holes used to hang garage doors and operators.
Perimeter Seal
Complete weather-stripping package for sectional garage doors, consisting of astragal, jamb seal and header seal.
Pinch Resistant
Term for a door that has been designed to prevent entrapping, crushing, breaking, severing or dislocating a person's finger.
Power Unit
A complete torsion spring assembly consisting of springs, shaft, winding plugs and stationary cones, drums and cables.
Galvanized steel is painted with a tough polyester coat to prevent rust. The finish may be painted by the customer if desired.
Coated with primer paint.
Pull Down Rope
A rope connected to the bottom bracket; used to manually pull the door down.
A wheel turning around an axis and having a groove on its rim in which runs a cable, chain, or rope.
The measurement of thermal efficiency of a door, or how well it insulates. The higher the R-value, the better it insulates.
The curved portion of the track, which allows the door to move from vertical to horizontal (and vice versa). The curve is measured in inches, thus determining headroom requirements.
Raised Panel
A raised panel provides a third dimension to the outside finish.
Rear Mount
When the counterbalance system attached to the rear of the horizontal tracks.
Residential Door
A sectional overhead type door which is intended for use in a residential garage, and normally operated less than 1,500 cycles per year.
Reverse Angle Mount
An L-shaped angle with the wall leg toward the door opening used to connect the vertical track to the jamb. Used in low headroom and side room restricted garages as well as lap joint.
Roller Assembly
The combination of a wheel and axle that is used to guide a garage door through the track system, either 2" (50.8 mm) or 3" (76.2 mm) diameter, depending on track size. Available as short or long stem.
Roller Bracket
A device that is mounted to a door section and holds a track roller.
Steel, ball-bearing wheels or nylon rollers that allow sections to roll freely along garage door tracks.
Hardware device used to connect an extension spring to a pulley. These are also used with other door related hardware (i.e., chain on locks).
Safety Cable
A cable threaded through an extension spring to retain the spring if it breaks.
Safety Spring Containment
An extra cable used with garage door extension springs to prevent it from causing damage or injury if the spring breaks. The cable is threaded through the center of the spring and is secured on both ends of the horizontal track.
Sandwich Door
Triple-Layer: Steel + Insulation + Steel Interior. Classica 3000, Heritage 3000, Stratford 3000 and Olympus (residential) and Models 2700, 1380, 1350, & 1000 (commercial).
Sectional Garage Doors
Garage doors made of two or more horizontal sections hinged together to provide a door large enough to close the entire opening. Sectional doors are guided into the horizontal or open position by a system of vertical or horizontal tracks. May be fabricated of continuous roll-formed steel with reinforcing ribs or flush sections of steel or aluminum.
A metal or plastic pulley that is designed to guide the cables employed in a counterbalance system.
Sheave Fork
A yoke type device used to attach the sheave to extension springs.
Side Room
A horizontal measurement from each side of the garage door opening outward along the wall to the nearest obstruction within the building.
Spring Assembly
Hardware used to make up the garage door counterbalance assembly.
Spring Pad
Pad installed on header above the door to anchor the center bearing bracket. Can be mounted in various locations, not necessarily in center, depending on size of springs.
Spring Pad (Center Bearing Plate)
Plate or bracket which is located on the wall above door opening to receive torsion spring assembly support brackets.
Stationary Cone
Part that fits into the end of a torsion spring permitting the spring to be fixed to the center bearing bracket. May also incorporate a retainer for a ball bearing or bushing.
Stock Door
Door made to standard size and generally kept in inventory at either distributor or factory warehouse.
Stop Molding
Seals the perimeter of the garage door against weather and light infiltration. Stop molding is nailed to the jamb, outside the door, and is incorporated as one of the final steps in the installation process. Sometimes called doorstop, it is usually wooden or plastic.
L-shaped metal reinforcement members attached horizontally to the inside of the garage door section to add strength and rigidity. Struts are necessary on wide heavy garage doors to help prevent sagging and bowing and to provide additional reinforcement to comply with the required wind-loading. Also called trusses.
Thermal Break
The separation between the outer and inner surfaces of a door section.
Act of twisting or turning of a torsion spring by the exertion of forces tending to turn one end about a longitudinal axis while the other end is held stationary.
Torsion Bar
A long metal bar that transfers torque from a spring to a winding plug.
Torsion Shaft
The shaft of a torsion spring assembly that transmits the lifting force of the torsion springs to cable drums and lifting cables.
Torsion Springs
Mounts above the garage door opening. The springs are manually wound, or charged, then set to a shaft that runs through the spring. The spring turns the shaft, which raises or lowers the door via the cables winding on drums.
Torsion Spring Assembly
Hardware used to make up door counterbalance assembly.
Garage door track usually consists of 4 pieces (2 vertical and 2 horizontal). The purpose of track is to provide a roadway for the roller wheels.
Track Bracket
A fixture, connected to a track, which is designed for the track to be mounted to the jamb.
Track Clip
A metal plate used to attach tract to wall angle.
Track Guard
Added protection for back of vertical track recommended in cases where powered material handling fork trucks and similar equipment may be operating in the area.
Track Roller
Roller assembly for guiding the door sections along track.
The finishing materials; such as the lock and handles on the door.
Triplex Spring
Three springs of increasing diameter assembled one inside another using special spring fittings.
Trolley Operator
Electric operator, which mounts above the door in the horizontal position and lifts door by pulling, and pushing the top section. Specifically designed for normal headroom and low headroom doors.
Truss (Struts)
Support stiffener used to increase wind load capacities of a door as well as reduce deflection of the door sections in the horizontal position.
Vertical Lift
A hardware design that allows a sectional garage door to open vertically along the wall above the door opening without turning back inside the building (commercial garage door application).
Warning Tag
A tag with warnings and/or instructions for safe operation.
Winding Cone
Part that fits into a torsion spring, permitting winding of the torsion spring and tension adjustment.
Winding Rod
A solid rod that fits into the socket of the winding plug to tension torsion springs.