This standard specifies the type 1 non-metallic insert hexagonal lock nuts with thread specifications M3~M36, performance grades 5, 8 and 10, and product grades A and B. 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 3098.9 and GB/T 3103.1).