Experimental study of the coefficient of friction in slip critical bolt joints

In order to confirm the slip factor, a series of experiments carried out on models of slip critical joints with contact surfaces subjected to shot blasting. The dependence of the slip factor on the technology of preparation of contact surfaces and the presence of a protective coating is established. The data obtained suggest that achieving the maximum guaranteed coefficient of friction of 0.58 requires careful control over the preparation of the contact surface. The absence of regulatory requirements for the technology of abrasive blasting and quality control of the friction surface is noted. Differences in approaches to the determination of the coefficient of friction between domestic and foreign methods are given. The expediency of revising the values of slip factor for various methods of surface treatment adopted in SP 16.13330.2017 for slip critical joints is substantiated.