This part of GB/T 6117 specifies the basic requirements for the type, size and marking of 7:24 tapered shank end mills with manual tool change. This part applies to 7:24 tapered shank end mills with a diameter greater than 23.6mm to 95mm.
GB/T 6117.3-2010 Referenced Document
GB/T 3837 7/24 tapers for tool shanks for manual changing
GB/T 6117.3-2010 history
2010GB/T 6117.3-2010 End mills.Part 3:Milling cutters with 7:24 taper shanks
1996GB/T 6117.3-1996 End mills--Part 3: Milling cutters with 7/24 taper shanks