Coach Bolts - Metric - Galvanised

Often called carriage bolts or cup square hex bolts, coach bolts have a round head with a square underside.

Coach bolts are available in a range of sizes. All have metric coarse threads. They are most commonly used in the construction and timber trades.

Metric is the most common thread type in production today. Usually specified as M then a number x another number. This signifies the thread diameter and the length of the fastener.

For example M4 x 30 means that the major thread diameter (the external distance across the outside of the thread) is 4mm and the length is 30mm. Length is usually measured from the underside of the fastener head.

The term galvanised refers to a protective zinc coating that is applied to products made from steel to prevent them from rusting.