Coach & Carriage Bolts

A Carriage Bolt, also known as a Coach Bolt or as a ‘Fully Threaded Cup Square Hex 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 rib neck Carriage Bolt has several longitudinal ribs instead of the square section, to grip into a metal part being fixed.