This standard specifies the dimensions of the end, shoulder distance, undercut and chamfer of ordinary threads for general fastening connections. The values of this standard can be used for the end, shoulder distance, undercut and chamfer of threads that are the same as or similar to ordinary thread profiles (for example: transition fit threads, large clearance threads, ultra-fine threads and small threads, etc.).
GB/T 3-1997 history
1997GB/T 3-1997 Run-outs, undercuts and chamfers for general purpose metric screw threads