This International Standard specifies the characteristics of hexagon socket head cap screws with threads from M1,6 up to and including M64 and product grade A. Gauging of hexagon sockets is specified in annex A. For approximate masses of screws see annex B. If, in special cases, specifications other than those listed in this International Standard are required, they should be selected from existing International Standards, for example ISO 261, ISO 888, ISO 898-1, ISO 965-2, ISO 3506-1 and ISO 4759-1.