This paper presents procedures developed for the calculation of the coefficient of friction of bolt/nut assemblies and for the calculation of torque specifications, which include the case where the fasteners have prevailing torque KEYWORDS: fastener torque, prevailing torque, torque calculation, head finish, thread finish β th Half flank angle of the bolt thread (π/6 for ISO thread) µ G

The Monte Carlo simulation method is applied to quantify the probability of exceeding the maximum desired bolt exploitation for fasteners tightened to a torque specification. The simulation results are utilized to develop a method for the calculation of torque specifications such that the probability that a bolt will exceed the maximum desired bolt exploitation is thirty-two parts per million (ppm).