Patent ID: 7175373

Claim:
A rotating tool ( 1 ) including a drill, a milling cutter, a countersink or a deburrer, comprising: a working part ( 4 ) to be driven in rotation about an. axis of rotation ( 2 ) for cutting or machining, a clamping shank ( 6 ) axially adjoining the working part ( 4 ) for insertion into a clamping chuck of a drive machine, the clamping shank ( 6 ) having at least two clamping surfaces ( 10 ) on an outer circumference thereof for supporting a clamping jaw ( 8 ) of the clamping chuck in each case, the clamping shank ( 6 ) having a shank radius (r) in a region of each clamping surface ( 10 ), which rises from a minimum shank radius (r min ) over a range of angle of rise (α 1 ) to a maximum shank radius (r max ), as seen in a predetermined direction of rotation ( 12 ) of the tool, and wherein the shank radius (r) rises continuously so that the clamping surface ( 10 ) is curved convexly in cross section.