This standard stipulates that the thread specifications are M1.6~M64, the performance grades are 14H, 04, 05, A2-035, A2-025, A4-035, A4-025, CU2, CU3 and AL4 grades, and the product grades are A and Grade B hexagonal thin nuts. Grade A is used for D<=16 mm; Grade B is used for nuts with D>16 mm. If other technical requirements are required, they should be selected from current standards (such as GB/T 196, GB/T 3098.2 and GB/T 3103.1).