This Pakistan Standard specifies the dimensions of plain parallel shanks for milling cutters (of diameters 4 to 63 mm). It is applicable to both single-ended cutters and double-ended cutters.
The dimensions of flatted parallel shanks are the subject of PS : 1646-11-1984.
Threaded shanks are excluded from these two International Standards.
The two shank types covered by PS : 1646/ I and II have the same dimensional characteristics (diameters and lengths) but different tolerances on diameters, namely :
—h8 for plain parallel shanks, commonly used for tools mounted in collets ;
—h6 for flatted parallel shanks intended to be mounted in chucks and secured with a clamping screw, and requiring an accuracy adjustment.