Bolt Representation

Bolts are indicated by their diameter and length. Common coarse threads are marked as M8*15, while fine threads are marked as M8*15*1. The pitch must also be specified. Coarse threads do not have a pitch specified; only fine threads do.

A bolt is a fastener consisting of a head and a shank (a cylinder with external threads). It requires a nut and is used to fasten two parts with through holes. This type of connection is called a bolted connection. Since the two parts can be separated by unscrewing the nut, a bolted connection is a detachable connection. Hex head bolts are the most common, while countersunk bolts are generally used where a connection is required.