scope:

This part of ISO 3338 specifies the dimensions of flatted cylindrical shanks for milling cutters - of diameters to for single-flatted shanks, to for double-flatted shanks and to for shanks with an inclined clamping surface. In the case of single-flatted shanks, it is applicable to both singleended cutters and double-ended cutters, as double-flatted shanks cannot admit single-ended cutters. The dimensions of plain cylindrical shanks and threaded shanks are given in ISO 3338-1 and ISO 3338-3, respectively. The two shank types covered by ISO 3338-1 and this part of ISO 3338 have the same dimensional characteristics (diameters and lengths) but different tolerances on diameters, namely: - h8 for plain cylindrical shanks, commonly used for tools mounted in collets; - h6 for flatted cylindrical shanks, intended to be mounted in chucks and secured with a clamping screw, and requiring an accuracy adjustment.