Joint Surface Treatment Of Bolts

This technical requirement specifies the technical requirements for the manufacturing, installation and inspection of the steel structure high-strength bolt auxiliary connectors of mobile machinery and equipment. The content not specified in this technical requirement shall be implemented in accordance with relevant national standards. This technical requirement applies to mobile mechanical steel structures that need to be connected by high-strength bolts.

Joint surface treatment

(1) Friction type high-strength bolt connection requires close contact with the joint surface at the joint and sufficient friction coefficient. When the design drawing does not specify the treatment requirements of the joint surface, the treatment shall be carried out according to the following regulations: sandblasting or shot blasting the high-strength bolt joint surface to remove rust, oil and other impurities on the surface to reach the Sa2.5 level standard , The roughness is 50~75μm, and the friction coefficient shall not be lower than 0.40. When there are provisions in the drawings, follow the provisions of the drawings.

(2) After treatment, the friction surface of the high-strength bolt connection should be protected from dirt and oil. It is strictly forbidden to make any mark on the friction surface of the high-strength bolt connection. It is necessary to prevent contamination of the connecting surface during storage in the factory, or during transportation or storage at the installation site. The installation unit should pay special attention to the cleanliness of the connection surface of the connection plate of the high-strength bolt and the parent body and the characteristics of the friction surface. It is not allowed to use a grinder to polish the connecting surface of the connecting plate and the connecting surface of the mother body.