Patent ID: 7094006

Claim:
A cutting tool comprising a tool body and a cutting insert secured by a fastener in an insert pocket of the tool body; the insert pocket comprising a base wall and first and second sidewalls extending generally uprightly from the base wall and a pocket through bore extending from the base wall to a peripheral wall of the tool body; the cutting insert comprising at least one cutting portion provided with a cutting edge and a support portion provided with an insert through bore having a cylindrical insert through bore wall and at least two circumferentially spaced apart support wings protruding radially inwardly from the insert through bore wall, each support wing having a sloping support surface with a given shape, the support wings being separated by support wing gaps; the fastener having a forward portion, a rear portion and a generally cylindrical intermediate portion therebetween, with a longitudinal axis extending through the rear and forward portions, the forward portion being provided with at least two circumferentially spaced apart clamping wings each clamping wing having a sloping generally rearwardly facing clamping surface having a shape corresponding to the given shape of the support surfaces, the clamping wings being separated by clamping wing gaps, the fastener being rotatable about the longitudinal axis between a clamping position and a non-clamping position, wherein in the clamping position the forward portion of the fastener is located in the insert through bore with each clamping surface overlying a corresponding support surface; wherein the clamping surface of each clamping wing is helical in shape lying on a given helix of a male screw thread and the support surface of each support wing is helical in shape lying on a helix of a matching female thread.