Glossary of Garage Door Opener Terms

Garage Door Terminology

• This Technical Data Sheet includes a compilation of commonly used terms, and may not be
considered complete from an industry viewpoint.
• The terms and definitions are not universal. Variations within the industry may exist with regard to
precise meaning.

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
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
A-Frame: 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
Anodize: A hard non-corrosive oxide film on the surface of aluminum
Astragal: See Bottom Weatherseal
Astragal Floor Rail: See Bottom Weatherseal
Astragal Retainer: See Bottom Weatherseal
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
Back Hang: Hanger fabricated from angle iron, which attaches the end of the horizontal tracks to roof
construction or ceiling
Backroom: 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
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
Bead: A strip of metal, vinyl, or rubber used to secure glass around the periphery of a pane
Black: 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: See Bottom Corner Bracket
Bottom Corner Bracket: A structural support located on the bottom section that holds track rollers and may
also provide for attachment of lifting cables
Bottom Corner Fixture: See Bottom Corner Bracket
Bottom Fixture: See Bottom Corner Bracket
Bottom Rail: The lower-most horizontal rail of a door section
Bottom Roller Bracket: See Bottom Corner Bracket
Bottom Weatherseal: Weatherstrip attached to the bottom rail of a door to seal against the floor
Bow: 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 angle 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
Bushing: A fixed or removable lining used to constrain, guide, or reduce friction
Cable: 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
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 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
Cam: 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
Ceiling: 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
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: Refers to sprocket or pocket wheel, connected to torsion spring shaft, imparting mechanical
advantage to open and close a door
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
Chill: A square shaft that connects an outside handle to an inside lock set or night latch
Clearance: The amount of side room, head room and back room required to properly install a sectional door
Clevis: 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: A sectional overhead type door which is intended for vehicular use at entrances of buildings such
as loading docks and service stations, and is normally operated less than 5,000 cycles per year
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 Corner 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
Counterbalance: 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
Counterweight: Design of door mechanisms using weights instead of springs to counterbalance door weight
Counterweight Balancing System: See Counterweight
Coupler: A device to connect two counterbalance shafts together, end-to-end
Coupling: See Coupler
“C” Strut: See Strut
C-Value: 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
Cycle: One complete cycle of a door beginning with the door in the closed position, then moving to the open
position and back to the closed position
Cylinder: The part of a key operated lock that accepts the key and contains the locking pins
Daylight Opening: Opening dimensions taken between face of jambs and between floor and header
DC: 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
Decal: 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
Depth: 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
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: See Daylight Opening
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
Dowel: 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
DSB: Acronym for Double Strength Grade B Glass
Duplex Spring: A combination of two torsion springs of different diameters telescoped within spring fittings
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, which includes a ball bearing
to support radial movement of a torsion shaft at each end
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
Escutcheon: 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
Extrusion: Fabricated shapes made by forcing hot aluminum, or plastic, billets through a die in an extrusion
press
False Louver Molding: Special angular shaped molding that gives an appearance of a slatted panel when fitted
together
Ferrule: 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
Flipper: 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
Galvanizing: Zinc coating to protect steel against corrosion
Garage Door Opener: See Operator
Garage Door Operator: See Operator
Gauge: 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
Glazed: 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
Guard Angle: See Track Guard
Gusset: Cast, extruded, stamped, or rolled aluminum corner reinforcement which is fastened in corners to
stiffen joints or corners
Gusset Plate: Hardware fastened to door header to help support the track assembly and spring assembly
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
Header: See Door Header
Header Seal: See Top Seal
Headplate: The supporting plate for the lifting drum located in line with the outer edge of the door
Headroom: Vertical clear space required inside above the door opening, and below the lowest ceiling
obstruction, required for proper 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
Hi-Lift: See High Lift
Hi-Lift Track: See High Lift Track
Hinge: 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
Inch-Pounds: 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 corner 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
Installation: Placing a door in position for use
Installer: 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
Insulation: Material having ability to reduce heat or cold transmission
Interior Lock: See Inside Lock
Intermediate Hinge: See Center Hinge
IPPT: 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
ISLO: Acronym for “inside looking out”
Jackshaft-Type Operator: Operator which is mounted on wall or ceiling, with drive provided to turn a torsion
shaft
Jamb: See Door Jamb
Jamb Angle: See Angle Mounted Track
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 weathertight 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 weathertight seal between door sections
Joint Bracket: See Splice Jamb Bracket
Joint Seal: See Section Joint Meeting Rail Seal
Keeper Plate: See Striker Plate
Key: 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
Keyed-Alike: Two or more lock cylinders intended to be opened with the same key
Keyed Shaft: A shaft that has an integrated key way
K-Value: Laboratory-determined value of thermal conductance of a material
“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 Corner Bracket
Lift Clearance: See High Lift
Lift Clearance Track: See High Lift Track
Lift Handle: Handle for manually operating a sectional door
Lift Plate: See Step/Lift Plate
Lintel: Beam provided over an opening to carry wall and/or roof loads over an opening
Lite: See Vision Lite
Lock: 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 Corner Bracket
Lock Strike: See Striker Plate
Long-Stem Roller: Roller with a shaft length of 7 inches or longer
Louver: 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
LSLO: Acronym for left side looking out
Lubricant: A substance used to lubricate
Lubricate: To make a surface smooth or slippery; to reduce friction
Maintenance: 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
MIP: 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: Post 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.
Muntin: A bar member supporting and separating panes of glass within a sash or door
Mutt: See Stile
Neoprene: 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
Oil: See Lubricant
Oil-Canning: A slight buckling in sheet metal, causing the appearance of waviness or unevenness
Opener: 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
Operator: Electric device used to control the up and down motion of the door
Outside Hook Up: Connection where the counterbalance cable is on the outside of the tracks
Outside Hook-Up Bottom Bracket: Bottom corner bracket where the cable is routed outside the tracks
Outside Pull: See Outside Hook Up
Overlay: Decorative ornaments of metal, wood or hardboard used for outside decoration of garage door
sections
Pan Door: A garage door composed of sheet metal door sections
Panel: A raised and decorative design on door sections
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
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
Pre-Finished: Finish characterized by galvanized steel painted with a primer, then given an oven-baked top
coat
Pre-Painted: See Pre-Finished
Prime: To lay on the first coat of primer paint
Prime-Painted: 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
Pulley: 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
Purlin: 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 design to be pushed onto a shaft instead of a typical threaded nut
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
Radial Force: A force generated from the center of an object toward the outside
Radius: See Horizontal Radius
Radius Track: See Horizontal Radius
Rail: 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
Red: 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: A sectional overhead type door which is intended for use in a residential garage, and normally
operated less than 1,500 cycles per year
Restraining Cable: See Containment Cable
Return: 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
Roller: 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
RSLO: Acronym for “right side looking out”
R-Value: Thermal resistance value; inverse of U-Value
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
Sash: 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
SC: Door opening size designation, denoting “single car”
Scarf Joint: Method of joining pieces of lumber together by gluing and pinning with wood dowels
Scribing: Cutting a door bottom rail to match the contour of the floor
Scutcheon: See Escutcheon
Section: 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: See Sectional-Type Door
Sectional-Type 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
Servicing: See Maintenance
SG: Refers to “single glazed”
Shaft Bearing: A bearing that is used to maintain torsion shaft alignment and reduce friction
Sheave: 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
Shoe Molding: See Quarter Round
S-Hook: 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
Sideroom: 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
Slant: The pitch of a roof
Smile: See Bow
Snap Latch: See Automatic Latch
Solar Glass: A type of tinted glass
Special Door: Non-standard door which must be custom manufactured and/or specified
Specifications: 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: See Center Bearing Bracket
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: See S-Hook
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
Sticker: See Decal
Stile: Vertical reinforcement member of a section
Stock Door: Door made to standard size and generally kept in inventory at either distributor or factory
warehouse
Stop: 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
Stress: The amount of work required of a spring at a desired cycle level
Stretch Spring: See Extension Spring
Strike: See Striker Plate
Striker: See Striker Plate
Striker Plate: A plate used in conjunction with a locking system to secure a lock mechanism
Strut: 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
Sweep: 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 Handle: A handle in the shape of a “T”
T Lock Handle: See T Handle
Tapered Vertical Track: See Inclined Track
TC: A designation of door opening size indicating an opening for two cars
Template: 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
Tin-Canning: See Oil-Canning
Tog-L-Loc: Method of mechanically securing two pieces of steel together without welding, riveting or bolting
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
Torque: The twisting force around an axis
Torque Bar: See Torsion Shaft
Torsion: 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 in the manner of twisting one end or part about a longitudinal axis while
the other end is held or turned in the opposite direction developing torque
Torsion Spring Assembly: Hardware used to make up door counterbalance assembly
Torsion Spring Counterbalance Assembly: See Torsion Spring Assembly
Torsion Tube: See Torsion Shaft
Torsion Tube Coupler: See Coupler
Track: 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
Trajectory: 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
Trim: 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
Truss: See Strut
Truss Bar: See Strut
Tubular Shaft: A hollow shaft
Turn: A 360-degree revolution of a component about its axis
Turns On Spring: See Winds On Spring
Twist: A form of warp caused by the twisting or winding of the edges of a rail
U-Bar: See Strut
U-Bar Stiffener: See Strut
U-Bar Truss: See Strut
“U” Strut: See Strut
U-Value: 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
Vent: 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 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.
Vision Lite: Glazing that is mounted in a door
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
Weatherseal: See Weatherstrip
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 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