A cup head bolt, also known as a coach bolt or carriage bolt, has a domed or countersunk head, and 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.
A cup head bolt, also known as a coach bolt or carriage bolt, has a domed or countersunk head, and 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.