This part of ISO 12164 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. This part of ISO 12164 specifies the shank of type T. It incorporates a grooved flange to enable automatic tool exchange. The tools may 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.