Classification and quality requirements of high-strength bolts

High-strength bolts are made of high-strength steel plates, or bolts that require a relatively large pre-tightening force, can be called high-strength bolts. What are the regulations on the classification and quality of high-strength bolts? The following editor will explain it for you. 1. Classification of high-strength waste bolts Friction-type high-strength bolts: applicable to the connection of beams and columns of steel frame structures, the connection of solid web beams, the connection of heavy crane beams in workshops, the connection of brake systems and key structures bearing dynamic loads. Pressure-bearing high-strength bolts: suitable for bending-resistant connections in static load test structures that allow a little rolling or prefabricated components that indirectly bear dynamic loads. High-strength bolts with compressive strength: When the bolt is subjected to bending, its fatigue limit is low, and under load, its bearing capacity will not exceed 0.6P (P is the allowable load of the bolt). Therefore, it is only suitable for use under static load test functions, such as flange connections of stressed components, T-shaped connectors, etc. 2. Frequently asked questions about the quality of high-strength bolts 1. Surface floating rust, oil stains, burrs on the edges of bolt holes, and welding tumors should all be cleaned up. 2. After the contact friction surface is treated, it must exceed the required scratch resistance index. The high-strength bolts used should have supporting nuts and sealing rings, and should be used according to the supporting facilities when used, and cannot be replaced. 3. The friction surface of the treated prefabricated components should not be stained with oil, sand and other impurities during assembly. 4. When assembling, the friction surface of the parts should be kept dry, and it is not allowed to work in the rain. 5. Strictly check and calibrate the deformation of the connected stainless steel plates before assembly. 6. During assembly, it is strictly forbidden to hammer the bolts to avoid damage to the bolt threads. 7. Check the electric wrench regularly during use to ensure the accuracy of the torque, and operate according to the correct tightening sequence. 3. Safety measures for high-strength bolts 1. The size of the spanner wrench used should be consistent with the size of the nut, and a waterproof sleeve should not be added to the small wrench. A dead wrench should be used for high-altitude operations. If a familiar wrench is used, it must be tied with a rope, and people must pay attention to safety. 2. When assembling the connecting bolts of steel components, it is forbidden to insert the connecting surface or touch the thread holes by hand. When picking up and placing the stainless steel plate, the fingers should be placed on both sides of the plate.