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Glossary of Terms for Door Repairs

Courtesy of DASMA


Glossary of terms for door repairs


3-Hole Adjustable Clip

See 3-Hole Cable Clip

3-Hole Cable Clip

Metal clip tied to end of extension spring cable to allow length adjustment

3-Hole Cable Connector

See 3-Hole Cable Clip

A–Go to Top

Accent Moulding

Half-round and square mouldings that provide a distinctive mode of expression to doors

Access Door

See Pass Door

Active Coils

The number of working coils in a torsion spring

Adjustable Cone

See Winding Plug

Adjustable Sleeve

See Winding Plug

Adjusting Rod

See Winding Rod

Adjusting Spring Cone

See Winding Plug

Aero Cable

See Aircraft-Type Cable


Support member used to fasten torsion spring assembly of a vertical lift door to the wall above the door opening

Air Infiltration

The leakage or passage of air through a door system

Aircraft Cable

See Aircraft-Type Cable

Aircraft-Type Cable

Several strands of galvanized wire rope braided together

Anchor Cone

See Stationary Cone

Anchor Plug

See Stationary Cone

Angle Brace

Lateral brace attached to back hang and roof construction or ceiling

Angle Iron

Length of L-shaped steel material generally used to support and brace rear of horizontal tracks from roof construction or ceiling

Angle Mounted Track

A method of fastening vertical track to a door jamb using a full height continuous angle


A hard non-corrosive oxide film on the surface of aluminum


A compressible or deformable seal provided on the bottom edge of a door

Astragal Floor Rail

See Bottom Weatherseal

Astragal Retainer

A component, mounted to the bottom edge of a door, that holds an astragal in place

Automatic Latch

An automatic door locking device

Automatic Opening Device

Quick opening mechanism recommended for installations requiring rapid automatic door opening without use of an electric operator

B–Go to Top

Back Hang

Hanger fabricated from angle iron, which attaches the end of the horizontal tracks to roof construction or ceiling

Back Jamb

Wood member on the inside surface of the garage, surrounding the door opening Backroom: Horizontal distance measured into a building from the door mounting surface to the first obstruction within the zone required to install or operate the door

Ball Bearing

A load bearing device that uses trapped rolling balls to reduce rotating friction

Ball Bearing Drum

Counterbalance drum with a ball bearing for smoother operation of heavier doors

Bar Joist

A lightweight truss adaptable for the support of roof decks


A strip of metal, vinyl, or rubber used to secure glass around the periphery of a pane


Color-marking convention to mark parts as Right Side, Left Wound

Blind Rivet

A type of fastener that mechanically joins two pieces of material together by means of a riveting tool

Booster Spring

Additional spring, usually an extension spring, provided to compensate for weakened counterbalance

Bottom Bracket

A structural support located predominantly on the bottom section that holds track rollers and may also provide for attachment of lifting cables. Bracket locations other than at bottom section corners are possible

Bottom Corner Bracket

See Bottom Bracket

Bottom Corner Fixture

See Bottom Bracket

Bottom Fixture

See Bottom Bracket

Bottom Rail

The lower-most horizontal rail of a door section

Bottom Roller Bracket

See Bottom Bracket

Bottom Weatherseal

Astragal or other weatherstrip attached to the bottom 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 “smiling” (corners turned up)

Box Strut

See Strut

Bracket Mounted

Method of fastening vertical track to jamb using jamb brackets

Bracket-Mounted Track

See Bracket Mounted

Breakaway Track

See Angle Mounted Track

Breakstem Rivet

See Pop Rivet

Broken Cable Device

A bottom fixture intended to prevent a door from falling in the event of cable breakage


See Back Jamb


A fixed or removable lining used to constrain, guide, or reduce friction

C–Go to Top


See Aircraft-Type Cable

Cable Clamp

Manufactured device used to secure two pieces of cable to each other

Cable Drum

Grooved drum, fitted on torsion spring shaft, onto which lifting cable is wound when door is pened

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 Length

Specific amount of cable required to properly operate door

Cable Safety Device

A bottom fixture designed to slow or stop the descent of a door in the event of a cable breakage

Cable Stop

A swaged fitting at the end of the cable to prevent slippage through a slot in a drum

Cable Stopping Device

See Broken Cable Device


Rotating piece that transfers rotary motion into linear motion

Cam Tube

Tube encasing a torsion spring assembly that imparts axial force

Carry-Away Post

A type of removable center post


Top horizontal surface in the interior of a garage

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 Bearing Support

See Center Bearing Bracket

Center Bracket

See Center Bearing Plate

Center Bushing

Metal or plastic bushing used with a center bracket to support a torsion tube

Center Cable

See Center Lift Cable

Center Clamp

See Center Lift Cable

Center Coupler

See Coupler

Center Coupling

See Coupler

Center Hinge

A hinge generally located on the intermediate stiles to allow sections to pivot as door opens. Also used as graduated edge hinge between bottom and intermediate section

Center Lift Cable

Additional cable assembly which is secured to outside of door at points toward the center of the door, used to provide extra lifting support for extremely wide or heavy doors

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: Vertical member of a door section which provides structural rigidity and location for center hinge attachment

Center Support Bearing

See Center Bearing Bracket

Center Support Track

See Center Track

Center Track

Added track giving additional support to preventing sagging of a door in the open or horizontal position. Often used with an exceptionally wide door, a heavy door or a door containing a pass door

Chain Hoist

A mechanical device used to raise and lower the door by use of a hand chain

Chain Hoist Operator

Jackshaft type operator to which chain hoist is attached

Channel Frame

Frame used in jamb construction consisting of steel channel shapes installed where the flanges of the shapes wrap around the corners of jambs

Channel Truss

See Strut


A square shaft that connects an outside handle to an inside lock set or night latch


The amount of side room, head room and back room required to properly install a sectional door

Clear Rail

See Solid Rail


See Sheave Fork

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

Commercial Door

A door which is intended for vehicular use at entrances of commercial buildings such as loading docks, service stations, parking garages and manufacturing plants

Containment Cable

A cable threaded through an extension spring to retain the spring if it breaks

Continuous Angle

See Reverse Angle Mount

Continuous Angle Mount

See Angle Mounted Track

Contour Track

Horizontal track that follows the contour of roof construction or ceiling

Corner Bracket

See Bottom Bracket

Corner Burn

A full-scale fire test performed in a specially constructed room, where the ignition source is located in the corner of that room, adjacent to the garage door

Cotter Pin

A half-round metal strip bent into a pin, whose ends can be flared after insertion through a slot or hole


To oppose or balance with an equal weight or force

Counterbalance Shaft

See Torsion Shaft

Counterbalance System

A system which counteracts the weight of a garage door to allow a reduced force to open and close the door

Counterbalance Tension

See Counterbalance


Weights provided instead of springs to counterbalance door weight

Counterweight Balancing System

See Counterweight


A device to connect two counterbalance shafts together, end-to-end


See Coupler

“C” Strut

See Strut


Heat rate flow through an insulating material when there is a temperature difference from outer to inner surfaces; not normally used in conjunction with thermal transmittance through garage doors


An action on the door from the fully closed position, to the fully open position, and returned to the fully closed position


The part of a key operated lock that accepts the key and contains the locking pins

D–Go to Top

Daylight Opening

Opening dimensions taken between face of jambs and between floor and header


Door opening size designation, denoting “double car”

Dead Coils

The number of coils rendered inactive by the spring plugs

Dead-End Cone

See Stationary Cone

Dead in the Head

The lack of counterbalancing when the door is in the open position, failing to keep the door fully open

Dead Load

A static applied load, or a load without movement, generally referring to the weight of the door


A template of information attached to a garage door, or in its vicinity, to convey relevant information concerning the garage door system

Decorator Angle

See Jamb Angle


See Backroom

Design Wind Load

Horizontal design load applied to a garage door based on such factors as wind speed, building height and door horizontal location

Direct Drive Chain Hoist

See Chain Hoist

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

Disconnect Hoist

See Disconnect Chain

Dock Door

A vertically acting door, typically sectional, used primarily to close a door opening adjacent to a loading dock

Door Casing

The framing members with which a door opening is finished

Door Check

A mechanical device to insure the self closing of a pass door or wicket

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 Framework

See Door Frame

Door Guide

See Track

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 Moulding

See Door Casing

Door Opener

See Electric Operator

Door Opening

The clear open width and height

Door Operator

See Electric Operator

Door Path

See Trajectory

Door Schedule

A list of door sizes, locations and special requirements shown on a construction document

Door Section

A single segment of a sectional door

Door Size

Door dimensions characterized by the width first and the height second

Door Stop

See Stop Mould

Door Travel

See Trajectory

D Shaft

A torsion shaft manufactured with a flat area allowing minimum rotation of affixed hardware

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 Low Headroom Track

See Double Track Low Headroom

Double Shaft

Double torsion spring shaft used when additional space is required to accommodate counterbalance spring lengths

Double Strength Glass

A grade of window glass lighter than plate glass and usually 1/8” thick

Double Thick Glass

See Double Strength Glass

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

Double Track Low Headroom

Addition of second pair of horizontal tracks to reduce the high point of travel of top section and permit door being mounted in area with minimum headroom facilities


Wooden pin for fastening wood usually glued in between stiles and rails to strengthen a joint

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 Cap

A projection over the head of a door opening, or on the top of a wall, to throw water clear of the building

Drip Lap

An angled weather seal provided between sections on steel doors in lieu of a rabbeted joint to prevent entrance of the elements

Driveway Post

Post mounted adjacent to a residential driveway to provide exterior location for key switch to actuate an automatic door operator

Drop-Off Weight

See Counterweight


Acronym for Double Strength Grade B Glass

Duplex Spring

A combination of two torsion springs of different diameters telescoped within spring fittings

E–Go to Top

Eased Edge

Rounded and sanded meeting rail edge

Eased Off

See Eased Edge

Eave Height

Height measured from the floor to the underside of an eave

Edge Grain

Wood in which the rings form an angle of 45 degrees or more with the surface of the pieces

Edge Hinge

See Graduated Edge Hinge

Electric Opener

See Electric Operator

Electric Operator

An electrically-powered device to control the opening and closing of a door

Electrical Interlock

Interlock to prevent door operation by an electric operator under certain conditions

Embossed Door Section

Door section featuring embossed panels

Embossed Panel

Panel containing surfaces raised in relief from a flat surface

Embossed Rosette

Special ornament or design accessory made of wood, hardboard or aluminum with designs raised in relief from the surface

Embossed Section

See Embossed Door Section

Embossed Steel Door Section

See Embossed Door Section

End Bearing Plate

Plate commonly used on torsion spring counterbalance units

End Bearing Support

See End Bearing Plate

End Bracket

See End Bearing Plate

End Hinge

See Graduated Edge Hinge

End Roller Hinge

See Graduated Edge Hinge

End Stile

Stile located at each end of a door section which provides for attachment of graduated edge hinges

End Stile Lock

See Inside Lock

End Stile Sealing Strip

Foamed plastic strip to seal sections at end stiles of steel and fiberglass doors


A plate surrounding the lock mechanism on outside of door

Exhaust Port

Opening in bottom section to accept hose to vent tailpipe exhaust

Extension Spring

Provides power or tension by stretching or pulling, and is usually mounted along the horizontal section of track extending from front of door opening to the back hang

Exterior Lock

Keyed lock on exterior of the door


Fabricated shapes made by forcing hot aluminum, or plastic, billets through a die in an extrusion press

F–Go to Top

False Louver Molding

Special angular shaped molding that gives an appearance of a slatted panel when fitted together

Faux Divided Lite

One piece of glass divided by muntons to appear as several lites


Metal ring or cap which is affixed to a cable by compressing so as to form a button or loop on the end of the cable

Finger Joint

Joint used in joining lumber together at ends of lumber pieces Finish Moulding: See Stop Mould

Finished Door Opening

See Daylight Opening

Finished Opening

See Daylight Opening

Fire Station Release

See Automatic Opening Device Flag: See Jamb Angle

Flag Angle

See Jamb Angle

Flag Bracket

See Jamb Angle

Flame Spread Index

A measurement of horizontal flame spread across a product specimen under controlled laboratory conditions; the product is compared to the performances of red oak, which is standardized to 100, and gypsum board, which is standardized to zero


See Automatic Latch

Floor Seal

See Bottom Weatherseal

Floor Step

See Rain Stop

Flush Design

See Flush Door

Flush Door

Door comprised of sections unbroken by visible rails and stiles where the facing of the entire door presents an even surface

Follow Roof-Line Hardware

See Contour Track

Follow-the-Roof Pitch

See Contour Track

Follow-the-Roof Track

See Contour Track

Front Mounted Low Headroom

Low headroom hardware where springs mount on torsion shaft above opening

Front-Mounted Spring

A counterbalance spring that is mounted to the header above the door

Full Vertical Lift

See Vertical Lift

Full View Section, Full Vision Section

A totally glazed section with various types of glass or clear plastic. Section formed of aluminum extrusions which will marry with steel or aluminum sections above and below

Full Vision Section

See Full View Section


Zinc coating to protect steel against corrosion

Garage Door

A vertically acting door, typically sectional or tilt-up, used primarily for vehicular access into a building

G–Go to Top

Garage Door Opener

See Operator

Garage Door Operator

See Operator


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


Fitted with panes of glass or clear plastic

Glazing Lite

See Vision Lite

Glazing Strip

Extruded plastic or rubber strips that fit against glazing and window frame to resist water infiltration

Graduated Edge Hinge

Hinge placed on edge of door sections allowing sections to pivot as door opens and closes. Hinges hold track roller and are graduated and numbered for correct placement to ensure flush fit of door against jambs when closed

Grease Packet

Lubricant enclosed in a small packet


Insert within a window, designed to give the appearance of divided lites

Guard Angle

See Track Guard


Metal reinforcement plate, angle or bracket which is fastened in corners to stiffen joints

H–Go to Top

Hang Down

The amount of the door that hangs down from the door opening when the door is in the open position

Hanging Iron

See Angle Iron

H-Column Jamb

Separation of two door openings where door track is to be mounted directly to H- Column


See Door Header

Header Seal

Weather-stripping mounted at opening header to seal the opening between header and curtain


Vertical clear space required above the door opening, and below the lowest ceiling obstruction, required for proper installation and operation of the door and its hardware

Heliarc Weld

A type of inert gas-shielded arc welding employing helium or argon

High Arc

See Trajectory

High Cycle Spring

Counterbalance springs with increased cycle life capability for high usage

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

High Moment Arm

Radius of a cable drum, including cable, at point of cable peel off from the drum High Trajectory: See Trajectory


See High Lift

Hi-Lift Track

See High Lift Track


Hardware item that joins door sections together, and allows sections to pivot independent of each other

Hinge Support Plate

Plate used to support the hinge mounting area, i.e. a backup plate

Hinge Tube

Tube used to connect two hinge leafs together

Hoist Electric Operator

Similar to a jackshaft-type operator but with an auxiliary emergency chain hoist in case of a power failure

Horizontal Angle

See Horizontal Track Angle

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 Reinforcing Angle

See Horizontal Track Angle

Horizontal Rise

The upward slope of the horizontal track which helps to start the door downward and helps maintain cable tension

Horizontal Track

Track used in the horizontal segment of a track assembly

Horizontal Track Angle

An “L” shaped angle affixed to the horizontal track to stiffen it

Horizontal Track Assembly

An assembly made up of horizontal track and reinforced with an angle that is used to both guide and support the door in the horizontal position

Horizontal Track Radius

See Horizontal Radius

Hot Off The Floor

Condition where the door has a tendency to lift off the floor

I–Go to Top


English unit of measurement of torque

Inclined Track

Tapered spacing of the vertical track away from the jamb, permitting weathertight closing of door against jamb and easy release for opening door by eliminating friction

Inside Hook Up

Connection where the counterbalance cable is on the inside of the track, between the door sections and the vertical track

Inside Hook Up Bottom Bracket

Bottom bracket where the cable is routed between the vertical track and the door sections

Inside Lock

Spring loaded, sliding deadbolt lock or spring latch operable only from interior of the door


Placing a door in position for use


Person placing the door in position for use

Insulated Door

Door sections containing insulating material

Insulating Glass

Multi-pane glass assembly containing air space between panes for insulation


Material having ability to reduce heat or cold transmission

Interior Lock

See Inside Lock

Intermediate Hinge

See Center Hinge


Acronyn 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


Acronym for “inside looking out”

J–Go to Top

Jackshaft-Type Operator

Operator which is mounted on wall or ceiling, with drive provided to turn a torsion shaft


See Door Jamb

Jamb Angle

See Wall Angle

Jamb Bracket

“L” shaped bracket used to connect the vertical track to the door jamb

Jamb Extension

Framing extensions of door jambs above opening height; required to support door track and spring assemblies

Jamb Guard

See Track Guard

Jamb Seal

See Stop Mould

Joint, Rabbeted

See Joint Shiplap

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

Joint Bracket

See Splice Jamb Bracket

Joint Seal

See Section Joint Meeting Rail Seal

K–Go to Top

Keeper Plate

See Striker Plate


A square piece of steel that slides into a key way to prevent parts from rotating on a shaft

Key Alike

See Keyed-Alike

Key Switch Control

Use of key switch to actuate a door operator in place of or in addition to a push- button or transmitter

Key Way

A groove, milled into an object, which when used with a key will prevent parts from rotating on a shaft


Two or more lock cylinders intended to be opened with the same key

Keyed Shaft

A shaft that has an integrated key way


Laboratory-determined value of thermal conductance of a material

L–Go to Top

“L” Strut

See Strut

Lag Screw

A heavy wood screw with a square or hex head and a coarse thread Lap Jamb: Condition where door sections lap the door opening on each jamb Lapped Joint: See Joint, Shiplap

Latch Lock

See Automatic Latch

Lateral Force

Force applied from or toward the side

Lift Bracket

See Bottom Bracket

Lift Clearance

See High Lift

Lift Clearance Track

See High Lift Track

Lift Handle

A handle attached to the inside or outside of a door section, to be grasped by hand when a door is to be operated manually

Lift Plate

See Step/Lift Plate


A horizontal member spanning and carrying the load above an opening


See Vision Lite


Device to secure door to vertical track(s) in the closed position

Lock Bar with Cremone

Rotating the cremone or lock bar disc from outside or inside will force lock bars into cut-outs in track to lock door

Lock-On Bottom Roller Bracket

See Bottom Bracket

Lock Strike

See Striker Plate

Long-Stem Roller

Roller with a shaft length of 7 inches or longer


An opening with slats or screening for ventilation

Low Headroom Hardware

See Low Lift Hardware

Low Lift Hardware

Low headroom accessories which enable a door system to operate in minimal headroom conditions

Low Moment Arm

Smallest radius, or distance from the shaft axis, to the center of the cable that regards cable peel off point on cable drums


Acronym for left side looking out


A substance used to lubricate


To make a surface smooth or slippery; to reduce friction

M–Go to Top


The act of keeping a door system in good working condition

Master Keyed

See Master Keying

Master Keying

Arrangement whereby cylinder locks, although fitted with different keyed cylinders, can be opened or locked by means of one master key

Meeting Rail

The top horizontal rail or bottom horizontal rail of any section that meets and joins to form a weatherproof seal

Metallurgist Report

A report or document that describes the composition of a metal

Mill Certification

A report or document from the producing mill that provides all pertinent data relative to the composition, structure, heat, etc. of a given metal

Minimum Headroom

See Headroom

Minimum Sideroom

See Sideroom


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

Modular Coordination

The dimensioning of building units so that they will fit together, and the use of building dimensions consistent with such coordinated sizes

Mounting Plate

Flat steel or wood member placed on the wall to accommodate spring supports, spring shaft bearings, chain hoists and mounting for operators

Movable Post

See Mullion, Door

Mullion, Door

A movable, vertical structure or post that spans from floor to lintel, to which is mounted the left hand tracks or guides of one door, and the right hand tracks or guides of an adjacent door. Divides an opening width to permit the use of two doors, and is movable, to permit the use of the full opening width

Mullion, Window

Framing member forming a divide between units of a window


A bar member separating panes of glass within a sash or door


See Stile

N–Go to Top


A synthetic rubber made by polymerizing chloroprene

Nicopress Sleeve

A two-hole aluminum or copper sleeve through which cable is passed. Swaging will upset the sleeve to form a loop at cable end

Normal Headroom

See Headroom

Normal Sideroom

See Sideroom

Numbered Hinge

See Graduated Edge Hinge

Numbered Panel

Area between stiles I.S.L.O. numbered left to right

Numbered Roller Bracket

See Graduated Edge Hinge

Numbered Section

See Door Section

Nylon Center Bearing

See Bushing

O–Go to Top


See Lubricant


A slight buckling in sheet metal, causing the appearance of waviness or unevenness

One-Piece Door

See Tilt-Up Door


See Operator

Opening Height

Distance from floor to the bottom of header

Opening Size

See Daylight Opening

Opening Width

Distance between jambs of the door opening


An electric or air-powered mechanism that opens and closes a door

Outside Hook Up

Connection where the counterbalance cable is on the outside of the tracks

Outside Hook-Up Bottom Bracket

Bottom bracket where the cable is routed outside the tracks

Outside Pull

See Outside Hook Up

Overhead Door

See Sectional Door

Overhead Garage Door

See Garage Door

Overhead-Type Door

See Sectional Door


Decorative ornaments of metal, wood or hardboard used for outside decoration of garage door sections

P–Go to Top

Pan Door

A garage door composed of sheet metal door sections


1. A flat or raised and decorative design between stiles on door sections; 2. A span between center hinges

Pass Door

A swinging pedestrian door built into a sectional door. Not recognized as an exit door by model codes

Pedestrian Door

Access door adjacent to upward acting doors. Used as a legal means of egress to avoid the use of a sectional door

Perforated Angle

Angled metal with a serried of punched holes used to hang garage doors and operators

Perimeter Seal

Weatherstrip installed at the perimeter of a garage door

Pinch Resistant

Term for a door that has been designed to prevent entrapping, crushing, breaking, severing or dislocating a person’s finger

Plastic Muntin

See Muntin

Pocket Wheel

A wheel or drum machined to receive the individual links of a chain; used to directly transmit power


A type of foam insulation commonly foamed in place by manufacturers of garage door sections

Pop Rivet

See Blind Rivet

Pounds Pull

Unit of force determined by dividing the torque by the moment arm of the drum

Power Unit

A complete torsion spring assembly consisting of springs, shaft, winding plugs and stationary cones, drums and cables


Finish characterized by galvanized steel painted with a primer, then given an oven-baked top coat


See Pre-Finished


To lay on the first coat of primer paint


Coated with primer paint

Pull Down Rope

A rope connected to the bottom bracket; used to manually pull the door down

Pull Rope

See Pull Down Rope

Pull Type Spring

See Extension Spring


A wheel turning around an axis and having a groove on its rim in which runs a cable, chain, or rope

Pulley Clevis

See Sheave Fork

Punched Angle

See Angle Iron

Punched Angle Brace

See Angle Brace

Punched Angle Iron

See Angle Iron

Punched Angle Track Hanger

See Back Hang


A horizontal roof member spanning between beams and trusses to which roofing is attached; commonly used in a pre-engineered, industrial type building

Push Down Spring

Spring-activated push rods mounted on horizontal tracks to start door down during closing portion of door cycle; generally used with a jackshaft-type operator or a manual chain hoist

Pusher Bumper

A leaf spring in place of a rod

Push Nut

Stamped metal fastener designed to be pushed onto a shaft to secure an assembly

Q–Go to Top

Quarter Grain

See Edge Grain

Quarter Round

Molding showing a quarter circle in its cross section

Quarter Turn

A unit of turn measurement when winding tension into a torsion spring Quick

Turn Bracket

See Low Lift Hardware

R–Go to Top

Radial Force

A force generated from the center of an object toward the outside


See Horizontal Radius

Radius Track

See Horizontal Radius


Horizontal member of a section

Rain Ledge

See Rain Stop

Rain Stop

Ledge provided at the point where the bottom rail meets the floor to prevent water from running under the door and allowing for runoff of the water onto the drive or approach

Raised Panel

See Panel

Rate of Rise

Measurement of change per revolution of a drum's moment arm

Rear Mount

When the counterbalance system attached to the rear of the horizontal tracks

Rear-Mounted Torsion

See Rear Mount

Rear Track Hanger

See Back Hang


Indicates color for Left Side, Right Wound

Regular Angle Mount

See Angle Mounted Track

Removable Center Post

Post/track assembly which substitutes for door jamb in wide door openings so that multiple doors may be used instead of a single large door, and which can be released and carried from an opening

Removable Jamb Wall

Wall designed to allow the use of two or more doors in a single opening with carry-away aluminum center posts that can be removed when doors are in up position

Removable Mullion

See Removable Center Post

Removable Post

See Removable Center Post

Residential Door

A sectional door which is intended for vehicular use in a residential garage

Restraining Cable

See Containment Cable


See Sideroom

Reverse Angle

See Reverse Angle Mount

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 sideroom restricted garages as well as lap joint

Rigid Strut

See Strut

Rigid Truss

See Strut

Roll-Away Post

See Removable Center Post


See Track Roller

Roller Assembly

See Track Roller

Roller Bracket

A device that is mounted to a door section and holds a track roller

Roller Stem

See Track Roller

Rounded Off

See Eased Edge


Acronym for “right side looking out”


Thermal resistance value; inverse of U-Value

S–Go to Top

Safety Bottom Bracket

See Broken Cable Device

Safety Bottom Corner Bracket

See Broken Cable Device

Safety Bottom Fixture

See Broken Cable Device

Safety Cable

See Containment Cable

Safety Spring Containment

See Containment Cable

Safety Spring Containment Kit

See Containment Cable


The framework which holds the glass in a window or door

Sash Muntin

One of the rabbeted bars into which glass is fitted in a sash containing two or more lights


Door opening size designation, denoting “single car”

Scarf Joint

Method of joining pieces of lumber together by gluing and pinning with wood dowels


Cutting a door bottom rail to match the contour of the floor


See Escutcheon


Garage door component that extends the full width of an opening; usually joined together by hinges

Section Joint Meeting Rail Seal

A weather seal between door sections

Section Joint Meeting Rail Type Seal

See Section Joint Meeting Rail Seal

Sectional Door

Door made of two or more horizontal sections hinged together so as to provide a door capable of closing the entire opening and which is by means of tracks and track rollers

Sectional Garage Door

See Sectional Door

Sectional Overhead-Type Door

See Sectional Door

Sectional-Type Door

See Sectional Door


See Maintenance


Refers to “single glazed”

Shaft Bearing

A bearing that is used to maintain torsion shaft alignment and reduce friction


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

Shiplap Section Joint

Section joint interface that steps up from one level to a second level from the front of the door to the back of the door

Shoe Molding

See Quarter Round


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)

Shop Drawings

Drawings provided by the manufacturer or door supplier to the architect-engineer showing the plans, sections, elevations, and details of the work required, submitted to assure proper interpretation of the intent of the architectural drawings

Side Bearing Plate

See End Bearing Plate

Side Seal

See Stop Mould


A horizontal measurement from each side of the door opening, outward to the nearest obstruction

Single Door

Commonly used to refer to smaller width doors used on one car openings

Single Strength Glass

See Single Thick Glass

Single Thick Glass

A type of sheet glass used in glazing sashes


The pitch of a roof


See Bow

Snap Latch

See Automatic Latch

Solar Glass

A type of tinted glass

Solid Rail

A rail made with one continuous piece of lumber without finger joints

Special Door

Non-standard door which must be custom manufactured and/or specified


A detailed statement of the quantity and type of material to be used in the construction of a garage door system

Splice Plate

Plate used for attachment of track at the junction of tracks in clip type angle mounted track

Spring Anchor

Winding Cone and Stationary Cone

Spring Anchor Bracket

See Center Bearing Bracket

Spring Anchor Cone

See Stationary Cone

Spring Anchor Plate

See Center Bearing Bracket

Spring Assembly

See Torsion Spring Assembly

Spring Assembly Closed Wound

A coiled torsion spring with no gaps between the coils

Spring Assembly Open Wound

A coiled torsion spring with equal gaps between each coil

Spring Balance

The amount of turns needed to counterbalance the weight of the garage door

Spring Bumper

Spring mechanism mounted on horizontal track that eases the door to stop in its upward travel to reduce shock and prevent pull down rope breakage. Can be made from leaf springs or tension rods

Spring Constant

Mathematically developed number from basic spring wire formulas, that applies to any specific wire size and coil diameter combination; used to determine the number of active coils a spring must contain

Spring Containment Device

See Containment Cable

Spring Fitting

A plug or cone used to adapt the torsion springs to the torsion shaft and/or center bearing bracket. One piece is a stationary cone while the other fitting is a winding plug

Spring Hook

A formed end of the counterbalance spring wire used to facilitate assembly

Spring Latch Lock

See Automatic Latch

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 Plug

See Spring Fitting

Spring Retainer

See Spring Fitting

Spring Winding Cone

See Winding Plug

Square Key

See Key

Standard Headroom

See Headroom

Standard Sideroom

See Sideroom

Stationary Bearing Retainer

See Stationary Cone

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

Stationary Plug

See Stationary Cone

Stationary Sleeve

See Stationary Cone

Stationary Spring Cone

See Stationary Cone

Steel Jamb

Door framing made from either channel or angle iron

Steel Jamb Mounted

A track system intended for mounting to a steel jamb

Steel Pin

Short, headless pointed nail driven through the dowel and rail in doors for greater security

Step Down Plate

A means of closing a sectional door the last few inches of its travel

Step/Lift Plate

A part that can be used as a step down plate and a lift handle for manually operating a sectional door


See Decal


Vertical reinforcement member of a section

Stile-and-Rail Garage Door

A sectional garage door featuring sections each made up of horizontal rail and vertical stile structural framing members that support panels connected to such members

Stock Door

Door made to standard size and generally kept in inventory at either distributor or factory warehouse


See Stop Mould

Stop Mould

Serves to seal the perimeter of the door against weather and light infiltration; usually nailed to the jamb, outside the door

Stop Moulding

See Stop Mould


The amount of work required of a spring at a desired cycle level

Stretch Spring

See Extension Spring


See Striker Plate


See Striker Plate

Striker Plate

A plate used in conjunction with a locking system to secure a lock mechanism


Support stiffener to reduce deflection of the door sections in the horizontal position. Also, to increase windload capability of a door

Sway Brace

See Angle Brace

Sway Strap

See Angle Brace


See Trajectory

Swing-Away Post

A type of removable center post that remains attached at the top and can be pivoted out of the way

Swing-Up Post

See Swing-Away Post

T–Go to Top

T Handle

A handle in the shape of a “T”

T Lock Handle

See T Handle

Tapered Vertical Track

See Inclined Track


A designation of door opening size indicating an opening for two cars


A pattern used as guide to shape something or show hole drilling locations. Also a short header to support a beam in a wall

Test Load

See Test Wind Load

Test Wind Load

Specified difference in static air pressure (positive or negative), equal to a specified percentage greater than or equal to 100% of the design load

Thermal Barrier

See Thermal Break

Thermal Break

The separation between the outer and inner surfaces of a door section

Thermal Seal

See Bottom Weatherseal

Tilt-Up Door

Door made of a single panel that pivots from the fully closed position to the fully open position which is horizontal and above the garage floor


See Oil-Canning


Method of mechanically securing two pieces of steel together without welding, riveting or bolting

Tongue and Groove Section Joint

Section joint interface commonly composed of a middle protrusion on a garage door section edge mating with a middle groove on an abutting section edge

Tongue and Groove Board

Vertical wood planks that when laid out side-by-side resembles wainscoting

Top Carrier

See Top Fixture

Top Fixture

A bracket for positioning the top guide roller on the top section of a door

Top Header Seal

See Top Seal

Top Rail

Horizontal rail forming the top of a door as distinguished from the meeting rails and bottom rail

Top Roller Bracket

See Top Fixture

Top Roller Fixture

See Top Fixture

Top Seal

Weatherstripping which fastens to the top of the door to seal the door along the top of the opening


The twisting force around an axis

Torque Bar

See Torsion Shaft


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

A shaft that transfers torque from springs to load

Torsion Spring

A spring that works by turning one end about a longitudinal axis while the other end is held or turned in the opposite direction developing torque

Torsion Tube

See Torsion Shaft

Torsion Tube Coupler

See Coupler


Channel shaped metal bars or rails in which upward acting doors operate via track rollers

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 Graduation

The differential distance from the track to the door jamb, measured at the top and bottom of the vertical track

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 Hanger Kit

See Back Hang

Track Radius

See Horizontal Radius

Track Roller

Roller assembly for guiding the door sections along track


The arc of travel or sweep of the top section as the door is raised from closed to open position

Translucent Door

Door that allows the passage of light without being transparent

Transom Bar

A horizontal crossbar in a window, over a door, or between a door and a window or fanlight

Transom Section

An extra section above a garage door opening sometimes used to allow extra lift of the horizontal tracks to accommodate a trolley type operator


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 Opener

See Drawbar Operator

Trolley Type Operator

See Drawbar Operator

True Divided Lite

A window composed of several smaller windows separated from each other by window mullions


See Strut

Truss Bar

See Strut

Tubular Shaft

A hollow shaft


A 360-degree revolution of a component about its axis

Turns On Spring

See Winds on Spring


A form of warp caused by the twisting or winding of the edges of a rail

U–Go to Top


See Strut

U-Bar Stiffener

See Strut

U-Bar Truss

See Strut

Urethane (Finish)

A clear finish commonly used as a top layer to finish wood

Urethane (Insulation)

See Polyurethane

“U” Strut

See Strut


Thermal transmission coefficient which is a measurement of heat, in BTU's, transmitted through one square foot of material (the door) in one hour at a temperature difference of 1 degree from one side to the other

Upper Trajectory

See Trajectory

Upper Vertical Track

Upper track assembly on a vertical lift door

V–Go to Top


Glossy clear top coat used on finished wood; may not be suitable for outdoor wood applications for its lack of breathability

Vehicle Access Door

See Vehicular Access Door

Vehicular Access Door

A door, typically a garage door or a rolling door, used primarily for vehicular access into a building


An opening located in the bottom section of a door for ventilation

Vertical Grain

See Edge Grain

Vertical Lift

Refers to a hardware design that causes doors to open vertically where no horizontal tracks are required

Vertical Lift Drum

A cable drum with changing radius grooves to negate spring tension

Vertical Post

A vertical reinforcement sometimes installed for high wind events

Vertical Splice Angle

See Jamb Angle

Vertical Track

The portion of track that is oriented vertically and is adjacent to the jamb

Vertical Track Assembly

An assembly made up of a piece of vertical track and a piece of continuous angle or jamb brackets used to secure the track to the jamb

Vertically Acting Door

A door that is typically a garage door or a rolling door

Vision Lite

Glazing that is mounted in a door

W–Go to Top

Warning Tag

A tag with warnings and/or instructions for safe operation

Water Seal

A coating of some kind used to prevent the absorption of water

Water Stop

See Rain Stop

Weather Joint

See Weatherstrip


See Weatherstrip


Material used at the perimeter of a garage door, or between joints of a garage door, intended to improve a door’s performance against air infiltration and thermal transmission

Wedge Connection

A device composed of a steel wedge and clip for securing the joint between vertical and horizontal track sections

West Coast Lumber

Lumber produced on the West Coast, generally used in manufacturing wood sectional garage doors

Wheel and Axle

See Track Roller

Wicket Door

See Pass Door

Wind Load

See Design Wind Load

Winding Bar

See Winding Rod

Winding Cone

Part that fits into a torsion spring permitting winding and tension adjustment

Winding Cone Set Screw

See Winding Plug Set Screw

Winding Cone Socket Head Set Screw

See Winding Plug Set Screw

Winding Plug

See Winding Cone

Winding Plug Set Screw

Set screw fasteners used to lock the winding plug to the torsion shaft

Winding Rod

A solid rod that fits into the socket of the winding plug to tension torsion springs

Winding Sleeve

See Winding Plug

Window Lite

See Vision Lite

Winds On Spring

The number of winding turns on a torsion spring

Wire Glass

Glass into which wire netting is woven prevent splintering from heat or impact

Wire Rope

See Aircraft-Type Cable

Wire Size

The diameter of the wire in a spring

Wood Anchor Pad

See Spring Pad

Wood Casing

See Wood Jamb

Wood Grain

Direction or orientation of the wood, as seen in a piece of lumber

Wood Jamb

Upright wood piece forming the side of an opening

Wood Jamb Mounted

Refers to mounting vertical track to wood jambs

Woodruff Key

Special half-moon shaped steel key

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