Abstract: Indexable insert has a non-rectangular parallelogram shape with nearly rhombic basic shape and an imaginary intermediate plane spanned by four corners of an imaginary rhombus with sides running at a distance away from the upper side and the underside along the peripheral lateral surface in a plane such that each equivalent cutting edge has the same variation of distance and angle from the intermediate plane. Two diagonally opposing corners of both the upper side and the underside each have a greater distance from the intermediate plane than do the respective diagonally opposing corners of the upper side and the underside lying therebetween, and the diagonally opposing corners of the upper side and of the underside are shifted parallel to the intermediate plane and, as viewed in a plan view onto the intermediate plane, in mutually opposite directions away from the associated diagonals of the rhombus spanning the intermediate plane.

Abstract: Indexable insert has a non-rectangular parallelogram shape with nearly rhombic basic shape and an imaginary intermediate plane spanned by four corners of an imaginary rhombus with sides running at a distance away from the upper side and the underside along the peripheral lateral surface in a plane such that each equivalent cutting edge has the same variation of distance and angle from the intermediate plane. Two diagonally opposing corners of both the upper side and the underside each have a greater distance from the intermediate plane than do the respective diagonally opposing corners of the upper side and the underside lying therebetween, and the diagonally opposing corners of the upper side and of the underside are shifted parallel to the intermediate plane and, as viewed in a plan view onto the intermediate plane, in mutually opposite directions away from the associated diagonals of the rhombus spanning the intermediate plane.

Abstract: In the production of rotor grooves, between the usual undercut-free opening of the groove with a disk milling cutter and profile milling by means of a high speed, high performance steel profile shaft milling cutter, a preliminary fine cutting operation is inserted, in which the profile form is premachined with a profile shaft milling cutter equipped with indexable cutting bits. The profile shaft milling cutter used for the purpose has a greater number of cutting surfaces at its tooth tips than at its tooth flanks. The cutting surfaces defined by overlapping, in circumferential direction, of the cutting edges of the indexable cutting bits are interrupted, so that substantially flat and hardly stiff chips are produced.