A Carriage bolt, also known as a Coach bolt or Cup Head, has a domed head
The shank is topped by a short square section under the head. The square section grips into the part being fixed (typically wood), preventing the bolt from turning when the nut is tightened. Suitable for fixing metal to metal or timber to timber in framing applications
Carriage bolts are used to provide a smooth finish in framing where building materials need to be fastened to applications such as timber frames, furniture, fencing, etc.