Provided is a surface-coated cutting tool including a base material and a coating including a super-multilayer-structure layer where A layers and B layers different from the A layers in composition are alternately laminated. The super-multilayer-structure layer includes an X area and a Y area those are alternately repeated. In the X area, A layers having a thickness A.sub.X and B layers having a thickness B.sub.X are alternately laminated. In the Y area, A layers having a thickness A.sub.Y and B layers having a thickness B.sub.Y are alternately laminated. The thickness A.sub.X is larger than the thickness A.sub.Y, and the thickness B.sub.X is smaller than the thickness B.sub.Y. Each of the A layers and the B layers comprising one or more elements selected from a group consisting of Ti, Al, Cr, Si, Ta, Nb, and W, and one or more elements selected from a group consisting of C and N.

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.

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 invention relates to a cutting insert holder, having a central axis and at least one first receptacle for fastening a first cutting insert to the cutting insert holder, and having at least one second receptacle for fastening at least one second cutting insert to the cutting insert holder, wherein the first receptacle and the second receptacle are arranged offset from each other in the circumferential direction about the central axis, wherein the first receptacle and the second receptacle are configured and arranged in such a way that a first rake face associated with an active main cutting edge of a first cutting insert arranged in the first receptacle has a first orientation along the circumferential direction, wherein a second rake face associated with an active main cutting edge of a second cutting insert arranged in the second receptacle has a second orientation along the circumferential direction).

A coated cutting tool for chip forming machining of metals includes a substrate having a surface coated with a chemical vapour deposition (CVD) coating. The coated cutting tool has a substrate coated with a coating including a layer of -Al2O3, wherein the -Al2O3 layer exhibits a dielectric loss of 106tan 0.0025, as measured with AC at 10 kHz, 100 mV at room temperature of 20 C.

Methods of machining a body to produce a chip wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body.

A method can include vibrating a hard turning tool, and contacting the hard turning tool to a spinning work piece while vibrating the hard turning tool to remove material from the spinning work piece. The method can further include moving the tool in an axial direction and/or radial direction relative to the work piece.

Methods of machining a body to produce a chip are provided wherein the body is formed of a material and in a state such that the material exhibits sinuous flow during a machining operation. The methods include providing a layer located on a surface of the body, and machining the body by causing engagement between a cutting tool and the body in a contact region below an area of the surface having the coating layer thereon and moving the cutting tool relative to the body to produce the chip having the layer thereon. The layer reduces sinuous flow in the material of the body and the chip is formed primarily by laminar flow.

Provided is a surface-coated cutting tool including a base material and a coating including a super-multilayer-structure layer where A layers and B layers different from the A layers in composition are alternately laminated. The super-multilayer-structure layer includes an X area and a Y area those are alternately repeated. In the X area, A layers having a thickness A.sub.X and B layers having a thickness B.sub.X are alternately laminated. In the Y area, A layers having a thickness A.sub.Y and B layers having a thickness B.sub.Y are alternately laminated. The thickness A.sub.X is larger than the thickness A.sub.Y, and the thickness B.sub.X is smaller than the thickness B.sub.Y. Each of the A layers and the B layers comprising one or more elements selected from a group consisting of Ti, Al, Cr, Si, Ta, Nb, and W, and one or more elements selected from a group consisting of C and N.

A surface-coated cutting tool comprises a hard coating layer that includes a TiAlN layer and is provided on a surface of a cutting tool body. In case the composition of the TiAlN layer is expressed by a formula: (Ti.sub.xAl.sub.1-x)N, 0.10x0.35 (here, x is in atomic ratio) is satisfied. In the TiAlN layer, a high Ti band-like region is present in a direction at 30 degrees or less with respect to a line normal to the surface of the cutting tool body. An average composition X of the Ti component in the high Ti band-like region satisfies (x+0.01)X(x+0.05), an average width W of the high Ti band-like region is 30 to 500 nm, and an average area ratio St of the high Ti band-like region is 3 to 50 area %.