This standard specifies hexagon socket pan head screws with thread specifications M2~M10, performance grades 4.8, A2-70, A3-70, CU2 and CU3, and product grade A. If other technical requirements are required, they should be selected from current standards (such as GB/T 193, GB/T 9145, GB/T 3106, GB/T 3098.1, GB/T 3098.6 and GB/T 3103.1).