Product Description

Bolt: mechanical part, cylindrical threaded fastener with nut. A type of fastener consisting of head and screw (cylinder with external thread), which needs to be matched with nut for fastening and connecting two parts with through hole. This kind of connection is called bolt connection. If the nut is unscrewed from the bolt, the two parts can be separated, so the bolt connection belongs to the detachable connection.

According to the thread type, it can be divided into two types: coarse thread and fine thread. The coarse thread type is not shown in the mark of bolt. According to the performance grade, bolts can be divided into 8 grades: 3.6, 4.8, 5.6, 6.8, 8.8, 9.8, 10.9 and 12.9, among which bolts above grade 8.8 (including grade 8.8) are made of low-carbon alloy steel or medium carbon steel and heat treated (quenching + tempering), which are generally called high-strength bolts, and bolts below grade 8.8 (excluding grade 8.8) are generally called ordinary bolts