Adopted by Japanese Camera Industry as national standard. Available in 3 head types: Pan, Oval and Flat head. Type 1 has smaller head diameter and shorter head than Type 3. Mostly used in small appliance and hardware, e.g. watches, remote controls, cameras, etc.
Precision Screw Specification, Nominal Dia, Pitch, Major Dia, Tolerance, Assembly Screws (single & double), Double assembly, pan machine screw with external tooth lock & plain washer, pan machine screw with spring lock & plain washer, Single assembly, pan machine screw with external tooth lock washer, pan machine screw with plain washer, pan machine screw with spring lock washer, hexagon head with plain washer