High strength bolt is a high-strength bolt, which belongs to a standard part. A very important feature of high-strength bolts is that they are limited to single use. Jinhua large nuts are generally used for permanent connection and are strictly prohibited from reuse. According to the stress state, it can be divided into friction type and pressure type; According to the construction process, it is divided into torsion shear high-strength bolt and large hexagon high-strength bolt.