A flat head bolt with a bearing surface that is countersunk to a 150 degree angle. Although flat, the head has a measurable side height causing it to protrude above its mating surface when it is completely tightened. Directly below the head is a square neck and a threaded section that has a unified thread pitch.
The square neck design keeps the bolt from turning as a nut is tightened. The flat head feature gives a lower profile on the front or top side of the fastening than a round head carriage bolt. Designed specifically, but not exclusively for the garage door industry.
