Suitable Pitch Difference of the Nut to Realize Anti-Loosening for Different Bolt Nominal Diameters

Abstract

The pitch difference nut can be used in automobiles and other industries to improve anti-loosening and fatigue strength with low cost. In this paper, based on the suitable pitch difference α experimentally obtained previously for JIS M12 and M16, the suitable pitch difference is discussed for other bolt nominal diameters. Here, the overlap thread length is calculated from the suitable α obtained for M12. Then, the same value of is assumed to estimate the suitable α for other diameters. The validity of this theory is confirmed through calculating the prevailing torque for other diameter by applying FEM analysis.