A multilayer hard film-coated cutting tool including a cutting tool body and a multilayer hard film formed on a surface of the cutting tool body, wherein the multilayer hard film comprises at least an upper layer and a lower layer; the upper layer is made of a Ti and Si compound layer; the lower layer is made of a multi-layered film of an A-layer and a B-layer, a layer thickness of the B-layer is equal to or thicker than a layer thickness of the A-layer, a ratio of the layer thicknesses of the A-layer and the B-layer being A-layer:B-layer=1:1 to 1:2, the multilayer hard films having 2 to 8 pairs of the A-layer and the B-layer in a case where a single pair is defined by a combination of a single A-layer and a single B-layer.

Methods of machining a component including multiple dissimilar materials are disclosed. One method may include making a first cut in the component to remove at least a portion of a hardest material in the component and making a second cut in the component along a second cutting-path that does not include the hardest material. The first cut may expose a cut surface in the component and the second cut may extend through the cut surface. The cuts may be made using a turning operation and different cutting tools may be used for the first and second cuts. The hardest material may have a hardness of at least 50 HRC and the remaining materials may have a hardness of at most 45 HRC. The disclosed methods may be used to form a thrust face surface in a shell and sun gear assembly to extend tool life and reduce scrap.

A composite sintered material contains cubic boron nitride particles and binder particles. The composite sintered material contains 40 vol % or more and 80 vol % or less of the cubic boron nitride particles. The binder particles contain TiCN particles. The composite sintered material shows a first peak belonging to a (200) plane of the TiCN particles in a range in which a Bragg angle 2 is 41.7 or more and 42.6 or less in an X-ray diffraction spectrum measured using a Cu-K ray as a ray source.

The present invention is directed to a surface-coated cubic boron nitride sintered material tool including a cBN substrate and a hard coating layer formed on a surface of the cBN substrate and having an alternate laminated structure of A layer and B layer. A peak of the grain size distribution of cBN grains in the cBN sintered material is present within a range of a grain size from 0.50 to 1.00 m. The A layer has a composition of (Ti.sub.1-xAl.sub.x)N (0.4x0.7 in an atomic ratio). The B layer has a composition of (Cr.sub.1-y-zAl.sub.yM.sub.z)N (0.03y0.6 and 0z0.05 in an atomic ratio). An X-ray diffraction peak of a (200) plane is present at a position of a diffraction angle of 43.6 plus or minus 0.1 degrees, and a plastic deformation work ratio of the B layer is 0.35 to 0.50.

A work holder includes: a first holding part having three attracting members that are arranged circumferentially apart from each other to attract an axial end face of an annular work; and a second holding part having a contacting member that is held in contact with an inner periphery or outer periphery of the work and restricts radial movement of the work.

The current invention proposes sharpening thin hardened metal blades with the hard turning process using a holder designed to hold the blades in a firm and stiff manner and a ceramic cutting tool held in a fixture. Generally, the cutting tool is held stationary in its fixture while the workpiece, in its holder, is rotated such that it repeatedly comes into controlled contact with the cutting tool. In sharpening operations such as proposed here, it is critical to (i) hold the workpiece firmly and rigidly, and (ii) position the cutting tool in a precise, predictable and reliable manner.

An assembly-type cutter includes a shank and a cutter head. The shank has a hole at one end. The hole has a receiving portion, which includes an internal thread and can be treated thermally for increased rigidity. The cutter head has a cutting portion and a connecting portion at opposite ends respectively. The connecting portion includes a threaded member and can also be treated thermally for increased rigidity. The cutter head and the shank are threadedly connectable via the connecting portion and the receiving portion. The threaded member includes a body portion, whose diameter is defined as a root diameter, and an external thread on the body portion. The body portion is slightly tapered such that a locus of the root diameter is inclined.

Problem: To provide a cutting tool formed from a silicon nitride-based sintered body having high fracture resistance and having residual stress of a rake face and a flank face in an appropriate range. Solution: A cutting tool (1) formed from a silicon nitride-based sintered body containing not less than 50 volume % silicon nitride-based phase and from 10 to 30 volume % titanium nitride phase, uses an intersection ridge portion of a rake face (2) and a flank face (3) as a cutting edge (4), has a residual stress applied to the titanium nitride phase that is tensile stress, and is such that the tensile stress applied to the titanium nitride phase in the rake face (2) is greater than the tensile stress applied to the titanium nitride phase in the flank face (3).

In the case of a tool holder having a receptacle for a cutting insert, in particular a tangential cutting insert having eight lips, having a lateral bearing surface, a rear bearing surface and a bottom surface, the bottom surface is quadrangular in plan view and has a raised supporting region which has two supporting surfaces, positioned obliquely with respect to one another, for the cutting insert.

A hard material which, when used as a material of a sintered material, makes it possible to obtain a sintered material with excellent abrasion resistance, a sintered material, a cutting tool including the sintered material, a method for manufacturing the hard material and a method for manufacturing the sintered material are provided. The hard material contains aluminum, nitrogen, and at least one element selected from the group consisting of titanium, chromium, and silicon, and has a cubic rock salt structure.