According to the state of force is divided into: friction and pressure type:
In fact, there are differences in the design and calculation methods. The friction type high-strength bolts are slid between the slabs as the ultimate bearing capacity. The high-strength bolts of the pressure type are slid between the slabs as the normal use limit state and the connection failure Limit state. Friction type high strength bolts do not give full play to the potential of bolts. In practical applications, the use of friction-type high-strength bolts should be used as a safe reserve for structures that are very important or subjected to dynamic loads, especially when loads cause reverse stresses. In addition to other places should be used pressure-type high-strength bolts to reduce the cost of connection.
According to the construction process is divided into: torsional shear high strength bolts and large hexagonal high strength bolts.
Large hexagonal high-strength bolts are high-strength grade of ordinary screws, and torsional shear high-strength bolts are improved hexagonal high-strength bolts, in order to better construction.
The construction of high-strength bolts must be screwed up before the first screw, the first high-strength bolts need to use the impact of electric wrench or torque adjustable electric wrench; and the end of high-strength bolts have strict requirements, the final twist-type high-strength bolts must be used torsional shear Type electric wrench, the final twisting torque type high strength bolts must use torque type electric wrench.
Large hex bolts consist of a bolt, a nut, and two washers. Torsional shear high strength bolts consist of a bolt, a nut, and a gasket.