Bell-shaped milling cutter for producing preferably profiled, arcuate grooves, has a main body in the form of a circular disk and a plurality of cutting edge carriers which extend substantially perpendicularly to the plane of the main body and which are arranged in succession in the peripheral direction along a circular path about the center of the main body and are mounted releasably to the main body. To provide a bell-shaped milling cutter having the features set out in the opening part of this specification, which permits simplified and less expensive production of arcuate grooves without having to forego the precise arrangement and orientation of the cutting bits of the known bell-shaped milling cutters, provided at the main body are positioning devices which permit mounting of the cutting edge carriers in a plurality of mutually different radial spacings on the main body.

A milling tool includes a tool body having a peripheral surface and a central rotation axis. A number of cutting teeth protrude from the peripheral surface, a front end set of the cutting teeth arranged along a front end portion of an imaginary helix concentric with the central rotation axis, and a back end set along a back end portion of the helix. The cutting teeth engage the workpiece successively, starting with the foremost cutting tooth of the front end set. The back end set includes at least three along the helix adjacent cutting teeth arranged at a constant first radial distance from the central rotation axis. The front end set has at least two adjacent cutting teeth arranged at an along the helix non-constant second radial distance from the central rotation axis. The second radial distance is smaller than the first radial distance and increases successively along the helix.

The invention relates to a milling tool for gear milling. The tool body is equipped with tangentially mounted milling inserts having four cutting edges and two holes, only one of which is utilized for a fixing screw in two of totally four index positions. By locating a screw hole in the seat of the milling insert at a distance from the radial support surface of the seat that is greater than the distance between an individual hole and a distal end of the milling insert, a clamping force is provided by means of the inherent elasticity of the fixing screw. In such a way, the milling insert is pressed against the radial support surface. By means of a transversal eccentricity, the milling insert is also pressed against a tangential support surface in the seat. By means of this construction, the two holes in differently long milling inserts can be formed with equally large distances from distal ends. Thereby, one and the same tool body can be equipped with differently long milling inserts.

There is shown a tool holder for a hob, which is embodied as a bore having a clamping device provided between a spindle and a counterholder, the clamping device having a centring clamping piece that is engageable in the hob and a receiving mandrel that is engageable in the hob, the receiving mandrel being braced with the centring clamping piece in order to mount the hob, wherein the centring clamping piece has a flange. In order to ensure the best concentric running properties in a stable manner, it is proposed that the centring clamping piece and the receiving mandrel each have a flange, which each mount a radial adjusting drive with at least one adjusting member that is adjustable with respect to the spindle and/or the counterholder in order to center the clamping device.