This standard is applicable to the shank diameter and drive square head size of straight shank rotary tools (such as reamers, taps, etc.). This standard includes two dimension series: basic series and auxiliary series, and the basic series should be used first.
GB/T 4267-1984 history
2004GB/T 4267-2004 Rotating tools with parallel shanks-Diameters of shanks and sizes of driving squares
1984GB/T 4267-1984 Rotating tools with parallel shanks--Diameters of shanks and sizes of driving squares