摘要
In order to study how to improve the overall performance of the operational metal bolt, based on the production process of an ordinary metal bolt used in understructure engineering, this paper focused on the existing problems of ordinary metal bolts identified by some survey and analysis. The results show that the structure of operational metal bolts is so unrea- sonable that the bolt tail is easily fractured by low load capacity. Furthermore, a new type of strong big-end metal bolt and its heat treatment and roughing processing technology were introduced. Through bolt tensile and metallographic tests, the property of the new big-end bolt was analyzed. The new findings indicate that after a special processing, the overall strength and plasticity of the bolt is greatly improved, and the grain of the bolt tail structure is refined, which would help build up favorable working conditions for bolt tails.