This bolt has a square shoulder under a rounded head (Mushroom Head) which resists turning when the nut is tightened or removed. The bolt is driven into a hole the same size as the shank and then hammered the rest of the way, where the square shoulder locks firmly into place.
This bolt has a square shoulder under a rounded head (Mushroom Head) which resists turning when the nut is tightened or removed. The bolt is driven into a hole the same size as the shank and then hammered the rest of the way, where the square shoulder locks firmly into place.