High strength bolt connection with the construction of simple, mechanical properties, and can replace them, fatigue, and dynamic loads, not loose, etc., is a promising method of connection.
　　High strength bolt is tightened with a special wrench nut, but to make a huge bolt pre-tension controlled through the nut and the plate, connected pieces of the same size also had a pre-stress. In the pre-pressure, are connected along the surface will have a greater friction, obviously, as long as the axial force is less than the friction, components will not slip, the connection will not be destroyed, this is the high strength bolt connection principle.
　　High strength bolt connection by connection between the contact surface to prevent friction between slip, in order to have sufficient contact surface friction, it is necessary to improve the component elements of the clamping force and increase the contact surface of the friction coefficient. Between components of the bolt clamping force is applied by the pre-tension to achieve, so the bolt must be of high strength steel, which is known as the high strength bolt reasons.
　　High strength bolt connection, the friction coefficient of the large size of the bearing capacity. Tests showed that the contact surface friction coefficient is mainly affected by the form and component material impact. In order to increase the contact surface of the friction coefficient, the construction is often used to be blasting, cleaning with a wire brush and other methods of connecting components within the contact surface for processing.
　　High strength bolt friction-and in fact there are two kinds of pressure.
　　1 friction type high strength bolt is designed to withstand shear criteria due to the load does not exceed the shear friction.
　　2 pressure type high strength bolt bolt is based on the shaft is not a bad cut will not be crushed or plates for the design criteria.