The reason why ordinary bolts and high-strength bolts are used in different places is because there are certain differences in their characteristics. The following editor will analyze this matter with you and see if you can help you answer your questions! The physical properties and calculation formulas of ordinary bolts and high-strength bolts are different. The bearing force of the high-strength nut increases the pre-tightening force P inside it, and then forms friction resistance on the contact area between the connectors to bear the external load, while the general bolt immediately bears the external load. The high-strength nut connection has the characteristics of compact structure, good physical properties, removable, fatigue-relieving, and no loosening under dynamic loads. It's a promising way to connect. For high-strength nuts, use a special wrench to tighten the bolts, so that the bolts have a large and controllable pre-tightening force. According to the nut and spacer, the same amount of pre-working pressure is caused on the connecting member. Under the influence of the pre-working pressure, the surface of the connector will also generate relatively large sliding friction. Obviously, as long as the axial force is lower than this frictional force, the prefabricated components will not roll and the connections will not be damaged. This is the basic principle of high-strength nut connection. High-strength nut connections are prevented by friction between the contact areas of the connectors. In order for the contact area to have sufficient sliding friction, it is necessary to increase the clamping force of the device and increase the friction coefficient of the contact area. The clamping force between prefabricated components is achieved by adding pre-tightening force to the bolts, so the bolts must use high-strength steel plates, which is why it is called high-strength bolt connection. In high-strength bolted connections, the coefficient of friction does not affect the load-carrying capacity. The results show that the coefficient of friction is mainly influenced by the contact area shape of the prefabricated component material. In order to ensure the friction coefficient of the contact area, the method of sandblasting and steel brush cleaning is generally used to repair the contact area of the components within the connection range. In fact, there are two main types of high-strength nuts: friction type and pressure-bearing type. The shear stress rule for friction-type high-strength bolts is that the shear stress generated by the design load must not exceed the sliding friction. Rolling bearing high-strength bolts are customized based on the principle that the rod body will not be damaged or the damaged plate will not be damaged. In addition, high-strength bolts cannot be reused many times.