Abstract: To support an indexable cutting insert (6a) cutting with an end edge and facing edge (7a) as well as circumferentially, with respect to both axially acting forces as well as radially acting forces, the tool body (1) is formed with an abutment surface (17) to accept radially directed forces against which the insert can be clamped; to accept axially directed forces, a holding screw (25) passing through an opening (22, 23) in the insert is formed with an accurately machined portion (28) fitting into an accurately machined portion (29) of a reception bore (27) for the screw, so that the holding screw, itself, acts as an accurately placed axial support for the insert (6a).

Abstract: To provide for positive guidance of a bolt formed with a conical enlarged intermediate portion holding a cutter bit by resilient deflection of the bolt in an enlarged recess portion of the cutter bit, the enlarged recess portion is formed as an elongated portion adjacent a bore in which the bolt is threaded, the elongated opening being additionally formed with conical surfaces concentric with the bore so that, prior to resilient deflection of the bolt, the bolt is positively guided and, thereafter, the elongated opening permits deflection of the bolt, the length axis of the elongated enlarged portion being directed towards an abutment surface on the tool body to securely clamp the bit against the abutment surface and determine the direction of resilient deflection of the bolt.

Abstract: To permit resharpening of cutter blades of a helical milling cutter, the cutter blades or bits of a multi-bit cutter have decreasing thickness, and are placed in grooves having the same helix radius, but the centers of the helical axes offset from the center of rotation of the cylindrical cutter body in the direction towards the associated groove, so that cutter blades of lesser thickness are still seated firmly in the bottom of the respective groove. Upon dulling of the cutters, the thinnest one of the cutter blades is discarded, the thickest one only replaced and the worn blades moved up one step along the circumference of the body into grooves which are progressively more shallow, to compensate for decrease in thickness of the respective cutter bits upon regrinding to resharpen the bits.