1. The friction surface of the high-strength bolt connection must meet the design requirements, and the friction coefficient must meet the design requirements. No residual iron oxide scale on the friction surface.
2. The treatment and storage time and storage conditions of the friction surface should be the same as the storage time and conditions of the friction coefficient test piece.
3. The friction surface of the construction site should be prevented from being polluted by oil and paint. If there is any pollution, it must be cleaned up thoroughly.
4. Adjust the torque wrench. According to construction technical requirements, carefully adjust the torque wrench. The torque value of the torque wrench should be the mechanical properties and tensile force of the large hexagon head high-strength bolts of different specifications.