The Properties of High Strength Bolt Connection Pairs with Hot-Dip Coating

Hot-dip coating can improve the longevity of the bolt connection pairs, but may be influence the pairs on the torque coefficient and tensile load. The torque coefficient and tensile loads of three specifications, two strength degrees and two surface states with and without hot-dip coating bolt connection pairs were tested. The results showed both the mean and standard deviation of torque coefficient of the bolt connection pairs were enhanced in case of the hot-dip zinc process, deals with the lubricant MoS2 they were both decreased and closed to the standard values. By contrast, the tensile loads were unaffected by the hot-dip process.