Abstract
Tightning characterestics that are torque coefficients and nut turning coefficients studied empirically on two level bolt lengths (2.5 times and 5.0 times the diameter), and four level diameters (16mm, 20mm, 22mm, 24mm). Experements were carried out at various temperatures (-20℃, 0℃, 20℃, 40℃). The bolt-sets used for the tests were JIS B 1186, F 10 T class high-strength bolts. The following conclusions were obtained from the experiments. The firm relation was observed between temperatures and torque coefficients, depending on the rolling friction coefficients between nut and bolt that change in accordance with temperature. The change of torque coefficients was some -6.15×(10)^<-4> per 1℃. But there was no co-relation between temperatures and nut turning coefficients.
