GarageDoorProHQ
Glossary

Garage door glossary

15 terms you will hear from a garage door technician, defined in plain English so you can tell what is on the quote.

Anatomy of a torsion-spring garage doorFront view of a garage door opening. A horizontal steel shaft runs above the door carrying two coiled torsion springs, with a cable drum at each end. A lift cable runs from each drum down to the bottom bracket of the door. The door itself is four hinged sections running in a vertical track on each side.1234567
Where the load actually travels: the springs carry the door’s weight, the drums convert that into cable pull, and the cables lift from the bottom bracket. Every expensive failure on this page happens somewhere on this drawing.

All terms

Cycle rating

The number of full open-and-close cycles a garage door spring is engineered to survive — 10,000 on a standard spring, 25,000 or more on a high-cycle spring.

Door balance

How well a garage door’s springs offset its weight — a balanced door stays put when stopped halfway with the opener disconnected.

Emergency release cord

The red cord hanging from a garage door opener’s trolley that disconnects the door from the opener so it can be moved by hand.

Extension spring

A long spring mounted parallel to each horizontal track that stretches as the garage door closes, used mainly on older and lighter doors.

Jackshaft opener

A wall-mounted garage door opener that drives the torsion shaft directly from the side of the opening instead of pulling the door along a ceiling rail.

Lift cable

A steel cable running from the bottom bracket of the garage door to the spring shaft, transferring the spring’s force to the door.

Limit switch

The setting that tells a garage door opener where the door’s fully open and fully closed positions are.

Photo-eye sensor

A pair of infrared safety sensors mounted near the floor on both sides of the garage door opening that reverse a closing door if the beam is broken.

R-value

A measure of a garage door’s resistance to heat flow — the higher the number, the better the door insulates.

Roller

A small wheel on each side of every garage door section that runs inside the vertical and horizontal track.

Rolling code

A remote-control security system that changes the transmitted code after every use so a captured signal cannot be replayed.

Torsion spring

A wound steel spring mounted on a shaft above the garage door opening that counterbalances the door’s weight as it opens and closes.

Track

The steel channel on each side of the opening that guides the garage door’s rollers, turning from vertical to horizontal at the curve.

Weatherstrip

The flexible seal along the bottom, sides and top of a garage door that closes the gap between door and opening.

Winding bar

A solid steel rod sized to fit a torsion spring’s winding cone, used to tension or release the spring in a controlled sequence.