This Part specifies the designation for shank end mills of solid or insert construction with a maximum diameter of 99.9 mm.
GB/T 20323.1-2006 history
2020GB/T 20323-2020 Milling cutters designation —Shank-type and bore-type milling cutters of solid or tipped design or with indexable cutting edges
2006GB/T 20323.1-2006 Milling cutters.Designation.Part 1: Shank type end mills of solid or tipped design
GB/T 20323.1-2006 Milling cutters.Designation.Part 1: Shank type end mills of solid or tipped design was changed to GB/T 20323-2020 Milling cutters designation —Shank-type and bore-type milling cutters of solid or tipped design or with indexable cutting edges.