With the continuous development of science and technology and the rapid development of social and economic development, steel structures have been more widely used in various fields such as highway bridges, multi-storey buildings, sports venues, and steel structure industrial plants. As a key connection method for steel structures, special bolted connections for steel structures have been widely used in manufacturing. In order to ensure the reliable connection of steel structure-specific bolt connections to steel structure engineering buildings, the technical standards for high-toughness large hexagonal bolt connection products and the technical standards for steel structure engineering construction and installation clearly put forward strict technical standards for torque coefficients. Bolted connection pairs, that is, the average torque coefficient of each bolted connection pair with bolt strength is 0.110 to 0.150, and its relative standard deviation should be less than or equal to 0.010. The manufacturer must inspect the product before leaving the factory and attach a certificate for testing the distortion index to each small box. Construction companies should carry out re-testing within the storage period before use. As a specific method of steel structure connection, bolt connection plays a key role in the connection of steel structures. There are more than 300 supporting standard fastener manufacturers in my country's fastener research institute, and nearly 1,000 Sino-foreign joint ventures and private enterprises. Most of them manufacture bolts now. Due to the good construction quality of special bolts for steel structures, this connection technology is widely used in many steel structures. However, the construction technical requirements of bolts are very high, and operators must strictly implement the operating procedures. Appropriately grasp the specifications of bolt assembly and processing technology, train all the staff who use them, and ensure the quality of assembly construction. On this basis, our company promises to ensure reliable product quality and timely after-sales maintenance services, so that many customers can buy our products with peace of mind.