Springs & Hardware
Flag Bracket
A flag bracket is an L-shaped steel fitting that connects the top of the vertical track section to the beginning of the horizontal track section on each side of a garage door. It is the structural corner piece at the transition point where the door stops travelling vertically and begins to travel horizontally into the garage.
A flag bracket is an L-shaped steel plate that forms the corner joining the top of the vertical track to the front end of the horizontal track. One is mounted on each side of the door. The door travels straight up along the vertical track, then turns the corner and travels overhead along the horizontal track. The flag bracket holds that corner at the right angle and carries the weight of the horizontal track.
The vertical track runs up from the jamb and bolts to the lower leg of the flag bracket. The horizontal track bolts to the upper leg and extends back into the garage. The flag bracket itself is lag-bolted to a jamb board or structural header at the side of the opening.
What the flag bracket connects:
- Below: the top of the vertical track, which guides rollers as the door rises
- Behind: the horizontal track, which holds the door in the open position
- To the wall: bolted through the jamb at the corner of the opening
The end bearing plate for the torsion shaft mounts nearby, often to the same jamb just above the flag bracket. Both fittings together set the geometry at the top corner of the door's travel path.
Common failure modes:
Flag brackets loosen over time from vibration. A loose bracket shows up as a gap between the vertical and horizontal track at the corner, misaligned rollers, or a clunking sound as the top roller passes the bend. For example, a bracket that has been vibrating loose for months may eventually let the horizontal track sag by half an inch, enough to cause the top roller to bind on every cycle. Check the lag bolts any time the door makes new noises near the top of travel.
Residential flag brackets come in 12-inch and 15-inch radius versions. The radius must match what was originally installed. A 12-inch bracket swapped for a 15-inch bracket changes the door's arc and may cause sections to bind or strike the spring assembly.
The back-hang bracket suspends the horizontal track from the ceiling a few feet behind the flag bracket, keeping the track level across its full run.
Related terms
Back Hang
A back hang is a steel bracket that suspends the horizontal garage door track from the ceiling. Learn where back hangs install and what happens when they fail.
View termLifting Cable
A lifting cable connects the bottom of a garage door to its cable drum. When the spring unwinds, the drum winds the cable and the door rises. Learn specs and failure signs.
View termTorsion Shaft
The torsion shaft transmits spring torque to cable drums to lift a garage door. Learn its specs, what attaches to it, and signs it has bent or failed.
View termCounterbalance System
The counterbalance system is the spring, cable, and drum assembly that offsets garage door weight. Learn the components, how torsion and extension systems differ, and what fails.
View termPeople also ask
Common questions related to flag bracket.
Why is the garage door bottom bracket so dangerous?
The bottom bracket at each lower corner anchors the lift cable, so it sits under the full pull of the torsion springs.
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