According to the state of force is divided into: fricti […]
According to the state of force is divided into: friction type and pressure type:
In fact, there are differences in design calculation methods. The friction type high-strength bolts have slippage between the plate layers as the ultimate bearing capacity; the pressure-bearing high-strength bolts have slippage between the plate layers as the normal service limit state, and the connection failure is used as the bearing capacity. Extreme state. Friction-type high-strength bolts do not fully exploit the potential of bolts. In practical applications, for very important structures or structures subjected to dynamic loads, especially when the load causes back stress, friction type high-strength bolts should be used. At this time, the unused bolt potential can be used as a safety reserve. In addition to this, pressure-bearing high-strength bolts should be used to reduce the cost.
According to the construction process, it is divided into: torsional shear high strength bolts and large hexagonal high strength bolts.
The large hexagonal high-strength bolts belong to the high-strength class of ordinary screws, while the torsion-shear-type high-strength bolts are an improved type of large hexagonal high-strength bolts for better construction.
The construction of high-strength bolts must be screwed before final tightening. For high-strength bolts, the impact wrench or torque-adjustable electric wrench must be used for the high-strength bolts. The high-strength bolts must have strict requirements for final tightening. For electric wrenches, high-strength bolts for the final tightening torque must use torque wrenches.
The large hexagonal strong bolt consists of a bolt, a nut, and two washers. Torsion-type high-strength bolts consist of a bolt, a nut, and a washer.