This part of ISO 26623 specifies dimensions for polygonal taper interfaces with flange contact surface — polygon-shanks for automatic and manual tool exchange to be applied on machine tools (e. g. turning machines, drilling machines, milling machines, and turn/milling centres, as well as grinding machines). A range of shank sizes is specified. These shanks incorporate a grooved flange to enable automatic tool exchange. The clamping can be realized by a circular groove using clamping segments or internal screw threads using centre-bolts. The torque is transmitted by form lock (polygon).