High-tensile扭剪 bolts in small sizes such as M12 are commonly used in M16 and M30. The performance of ultra-large扭剪 bolts is unstable, so they should be used with caution in design. The difference between friction-type and pressure-type connections for high-tensile扭剪 bolts lies in: The connection of high-tensile扭剪 bolts is achieved through the扭剪 bolt shank, which applies a large clamping pre-tension to the connection plate, generating sufficient friction to enhance the integrity and rigidity of the connection. When subjected to...

During shearing force, depending on the design and mechanical requirements, there are two types: high-strength shear bolt friction connections and high-strength tension bolt compression connections. The fundamental difference between them lies in their states. Although they are the same type of tension bolt, there are significant differences in calculation methods, requirements, and application scopes.

In shear design, the high-torque bolt friction connection is in a state where, when the external shear force reaches the possible friction force, the contact surface between the torque shear bolt's clamping force is sheared.

That is to say, ensure that the internal and external shear forces connected do not exceed the frictional force throughout the entire lifespan of the connection. There is no relative sliding deformation (the clearance between the screw and the wall of the hole remains the original amount), and the connecting plate is subjected to overall elastic forces. In shear-resistant design, in high-strength torsion-shear bolt bearing connections, it is permissible for the external shear force to exceed the maximum frictional force, resulting in relative sliding deformation between the connecting plates until torsion-shear

The bolt shank contacts the wall of the hole. From that point on, the connection relies on the shearing of the bolt body, the pressure against the hole wall, and the friction between the plate contact surfaces, with the connection shearing state being characterized by the shearing of the bolt body or the pressure against the hole wall. In summary, friction-type high-strength tension-torque bolts and pressure-bearing high-strength tension-torque bolts are actually the same type of tension-torque bolt, regardless of whether the design considers sliding or not.

Friction-type high-tensile bolts cannot slide; they do not bear shear forces. Once they slide, the design reaches a destructive state, which is technically mature. Compression-type high-tensile bolts can slide and do bear shear forces; failure is equivalent to the destruction of a common bolt (either the bolt is sheared or the steel plate is crushed).