This standard specifies the unspecified tolerance grades and values of straightness, flatness, coaxiality, and symmetry of metal stamping parts, and specifies the unspecified tolerance levels and values of roundness, cylindricity, parallelism, perpendicularity, and inclination of metal stamping parts. Note the tolerance. This standard applies to sheet metal stampings.
GB/T 13916-2013 history
2013GB/T 13916-2013 Unnoted tolerance of shape and position for stamping parts
2002GB/T 13916-2002 Unnoted tolerance of shape and position for stampings