The difference between the special-shaped bolt and the common bolt

1. The special-shaped bolt is the bolt called the special-shaped bolt without the national standard. It is usually used in special occasions and special purposes. The difference between the general bolt and the general bolt is whether there is a national standard.
2, bolt: a mechanical part, a cylinder with a screw threaded fastener with a nut. A fastener consisting of two parts, the head and the screw (with external thread), is matched with nuts to fasten and connect two parts with through holes. This form of connection is called a bolt connection. If the nut is swirled from the bolt and the two parts can be separated, the bolt connection is a detachable connection.