ISO 12164-3:2014 specifies dimensions for hollow taper shanks with flange contact surface (HSK) to be applied to machine tools (e.g. turning machines, turning-mill machines). A range of shank sizes is specified.
Specified is the shank of type T. It incorporates a grooved flange to enable automatic tool exchange. The tools can also be exchanged manually via a hole in the shank taper.
The torque is transmitted at the tail end of the shank through keys as well as friction.