This standard specifies the prevailing torque test for automobile lock nut.^{Note 1)}

^{Note 1)} It is called a prevailing torque type nut and classified into 2 types as follows.

1 A type, a portion of bearing surface is deformed for prevention of loosening.

2 A type, resin is inserted in inside bearing for prevention of loosening.

PURPOSE

This standard aims at helping test personnel perform the test in an appropriate method by describing the test method of prevailing torque for lock nut used for preventing malfunction of mating parts due to loosening, as fastened to main function parts to which dynamic stress is applied for automobiles.