A clearance angle, of a blade-like tool or tool tooth of a tool for hob peeling workpieces is determined by defining the rake face contour of the tool and calculating the progression of path movement of the rake face during chip-breaking hob peeling, taking into account a pre-determinable transmission ratio between the tool and the workpiece determined by the respective number of teeth, and the desired tooth cross-section contour of the tool, and determining a tangential speed for points of the cutting edge of the tool during chip-breaking, wherein hob peeling is determined in the form of vectors that are displayed graphically as bundles for each point on the cutting-edge and a closed envelope surface is determined, which plus a desired clearance angle is selected as the shape for the flank face contour of the tool or of the flank face of the tool tooth. A tool is also provided.

A hard coating film of a coated cutting tool contains Al within a range of 70 at % to 80 at % and Ti within a range of 20 at % to 30 at % with respect to a total amount of metallic (including metalloid) elements, and contains Ar of 0.50 at % or less with respect to a total amount of the metallic elements (including metalloid) and nonmetallic elements. The film has a diffraction peak due to each of a TiN (111) plane, a TiN (200) plane, and a TiN (220) plane of an fcc structure and an AlN (100) plane and an AlN (002) plane of a hcp structure, in which the diffraction peak of the TiN (200) plane indicates a maximum intensity and an intensity of the diffraction peak due to the TiN (111) plane is next thereafter. The average crystal grain size is within a range of 5 nm to 50 nm.

A hard coating film of a coated cutting tool contains Al within a range of 70 at % to 80 at % and Ti within a range of 20 at % to 30 at % with respect to a total amount of metallic (including metalloid) elements, and contains Ar of 0.50 at % or less with respect to a total amount of the metallic elements (including metalloid) and nonmetallic elements. The film has a diffraction peak due to each of a TiN (111) plane, a TiN (200) plane, and a TiN (220) plane of an fcc structure and an AlN (100) plane and an AlN (002) plane of a hcp structure, in which the diffraction peak of the TiN (200) plane indicates a maximum intensity and an intensity of the diffraction peak due to the TiN (111) plane is next thereafter. The average crystal grain size is within a range of 5 nm to 50 nm.

The present disclosure relates to an apparatus for chamfering at least one edge of the gearing at the front side of a workpiece having internal gearing comprising at least one rotatably supported workpiece holder for holding the workpiece and comprising at least one rotatably supported tool holder for holding a chamfer hob, possibly a chamfer cut hob, wherein the tool holder is arranged at an internal hob arm whose free end can be traveled by a machine axis of the apparatus at least partly into the center opening formed by the internal gearing of the workpiece.

A surface-coated cutting tool has a rake face and a flank face, and includes a base material and a coating formed on the base material. The base material has a cutting edge face connecting the rake face to the flank face. The coating includes an aluminum oxide layer containing a plurality of aluminum oxide crystal grains. The aluminum oxide layer includes: a first region made up of a region A on the rake face and a region B on the flank face; a second region on the rake face except for the region A; and a third region on the flank face except for the region B. The aluminum oxide layer satisfies a relation: ba>0.5, where a is an average value of TC(006) in the first region in texture coefficient TC(hkl), and b is an average value of TC(006) in the second or third region in texture coefficient TC(hkl).

The invention relates to a method for machining a toothing that is chamfered on a tooth head front edge, in which a material projection resulting on said tooth head front edge chamfer, caused by chamfer formation on a tooth front edge of the toothing by means of plastic deformation, and/or caused by removing a primary/secondary burr produced on said end face during production of the toothing and, if applicable, formation of the tooth front edge chamfer, is removed in a rotational operation by a machining procedure with a machining tool that has a cutting edge.

A sintered material includes cubic boron nitride grains and a binder, a grain size D50 of the cubic boron nitride grains when a cumulative value of the cubic boron nitride grains is 50% in an area-based grain size distribution being more than 0.5 m and less than or equal to 5 m, more than or equal to 70 volume % and less than or equal to 98 volume % of the cubic boron nitride grains being included in the sintered material, the binder being composed of A.sub.1-xCr.sub.xN, where 0x1, and a remainder, the remainder being composed of at least one of a first element and a compound including the first element and a second element, the first element being one or more elements selected from a group consisting of W, Co, Ni, Mo, Al, and Cr, the second element being one or more elements selected from a group consisting of nitrogen, carbon, oxygen, and boron.

A surface-coated cutting tool includes a base material and a coating film formed on a surface of the base material. The coating film includes a first alternating layer and a second alternating layer formed on the first alternating layer. The first alternating layer includes first and second layers. The second alternating layer includes third and fourth layers. One or a plurality of the first layers and one or a plurality of the second layers are layered alternately, and one or a plurality of the third layers and one or a plurality of the fourth layers are layered alternately.

A method for machining toothed and hardened work wheels, includes: mounting a work wheel that is hardened and pre-toothed with an allowance onto a workpiece spindle; removing at least 50% of the allowance by means of gear skiving with a skiving wheel that is rotatably driven by a tool spindle; precision-machining the work wheel in unchanged tension by means of a honing wheel. The forward movement occurs during gear skiving in the extension direction of the toothing. The delivery of the workpiece that is moved in an oscillating manner in the extension direction of the toothing occurs during honing in the radial direction. The skiving wheel and the honing wheel are driven by a common tool spindle. A device for carrying out the method includes a workpiece spindle, which is driven to rotate, and a tool spindle, which carries a combination tool having a skiving wheel and a honing wheel.

The invention relates to a method for machining a workpiece, wherein, in particular in the skiving process, a toothing is produced on the workpiece in a first machining operation, in which a toothed cutting wheel, which rotates about the axis of rotation thereof and, on a first end face, comprises cutting edges on the toothing thereof, is coupled in a rolling manner to the workpiece which rotates about the axis of rotation thereof, and a cutting movement of the cutting edges, which has directional components in parallel with the workpiece axis, ends at an axial side of the workpiece toothing, the cutting edges of the cutting wheel forming a first operating region which can be positioned with respect to the workpiece by means of movement axes, and in which, in a second machining operation using a second operating region, the workpiece is machined on the side of the workpiece toothing at which the movement ends, wherein the second operating region can be positioned with respect to the workpiece by means of the same movement axes as the first operating region, and in particular is coupled for movement to the first operating region.