This standard stipulates that the thread specifications are M8X1~M64X4, fine thread, performance grades are 04, 05, A2-025, A4-025, A2-035, A4-035, CU2, CU3 and AL4 grades, product grades are A and Hexagon thin nuts with class B chamfer. 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 3098.4, GB/T 3098.15 and GB/T 3103.1). Coarse tooth nuts specified in GB/T 6172.1 should be preferred.