A process for producing a tool having a main body which extends in a longitudinal direction and at least one blade for machining a workpiece includes providing a base coating on the tool; grinding the at least one blade in a manner that removes the base coating in the region of the at least one blade; and providing a second, fine coating, to the at least one ground blade.

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 cutting tool includes a base material, and a coating film covering the base material in contact with the base material. The base material is a cubic boron nitride sintered material. The coating film is a ceramic. An amount of oxygen in the coating film is less than or equal to 0.040 mass percent.

A hard film for coating a surface of a base material, the hard film includes a layer A, a layer B, and a nanolayer-alternating layer. The layer A is an AlTiCr nitride of (Al.sub.aTi.sub.bCr.sub.c?.sub.d)N, where ? is one or more elements selected from C, B, Si, V, Y, Zr, Nb, Mo, Hf, Ta, and W. The layer B is an AlTiCr nitride or AlTiCr carbonitride of (Al.sub.eTi.sub.fCr.sub.g?.sub.h)C.sub.xN.sub.1-X, where ? is one or more elements selected from B, Si, V, Y, Zr, Nb, Mo, Hf, Ta, and W. The nanolayer-alternating layer is formed by alternately laminating a nanolayer A or a nanolayer B having the same composition as the layer A or B. And, the layer C is an AlCr(SiC) nitride or AlCr(SiC) carbonitride of [Al.sub.iCr.sub.j(SiC).sub.k?.sub.1]C.sub.YN.sub.1-Y, where ? is one or more elements selected from B, Ti, V, Y, Zr, Nb, Mo, Hf, Ta, and W.

A drill bit includes a body having a first end, a second end opposite the first end, and an axis of rotation extending centrally through the body. The drill bit includes a cutting head with a cutting tip on the axis of rotation and a cutting portion. The cutting portion includes first tip surfaces on opposite sides of the axis of rotation and second tip surfaces on opposite sides of the axis of rotation. Each first tip surface extends radially outward from the cutting tip to a corresponding second tip surface. Each second tip surface extends from a corresponding first tip surface to an outer periphery of the body. The first tip surfaces define a first tip angle measured through the axis of rotation that is oblique. The second tip surfaces define a second tip angle measured through the axis of rotation that is smaller than the first tip angle.

This surface-coated cutting tool includes a cutting tool body made of tungsten carbide-based cemented carbide and a hard coating layer deposited on a surface of the cutting tool body, in which the hard coating layer has at least one (Ti.sub.1-xAl.sub.x)N layer (0.4X0.7, X is an atomic ratio) with an average layer thickness of 0.5 to 10 m, the (Ti, Al)N layer has a cubic crystal structure, and IaIb<5 is satisfied when Ia (%) is an average absorptance of the hard coating layer at a wavelength of 400 to 500 nm and Ib (%) is an average absorptance of the hard coating layer at a wavelength of 600 to 700 nm.

A rotary cutting tool includes a base material, a first diamond layer, and a second diamond layer. The base material includes a head portion, a body portion, and a shoulder portion defining a boundary portion between the head portion and the body portion. The first diamond layer covers the body portion and the shoulder portion and exposes the head portion. The second diamond layer covers the head portion, is provided on the first diamond layer in the shoulder portion, and does not cover the body portion.

A coated cutting tool includes a body and a PVD coating disposed on the body. The body being cemented carbide, cermet, ceramics, polycrystalline diamond, polycrystalline cubic boron nitride based materials or a high speed steel. The coating includes a first layer of (Ti1-xAlx)N wherein 0.3x0.7, and a second layer of (Ti1-p-qAlp Siq)N with 0.15p0.45, and 0.05q0.20, wherein the second layer is deposited outside the first layer as seen in a direction from the body.

A coated cutting tool has at least one rake face and at least one flank face and a cutting edge therebetween. The coated cutting tool includes a substrate and a coating. The coating includes a (Ti,Al)N layer. The (Ti,Al)N layer is either a single monolithic layer or a multilayer of two or more alternating (Ti,Al)N sub-layer types having different compositions. The (Ti,Al)N layer has an overall atomic ratio Al/(Ti+Al) of >0.67 but ?0.85, wherein the (Ti,Al)N layer shows a plane strain modulus distribution along a direction perpendicular to a cutting edge on the rake face and/or the flank face. The plane strain modulus at a point at a distance of 0.5 mm from a point at the cutting edge is more than 85% of the plane strain modulus at the cutting edge, with the plane strain modulus at the cutting edge being ?450 GPa.

A coated cutting tool has a substrate and a coating layer formed onto a surface of the substrate. The coating layer contains a hard layer of a composition represented by (Ti.sub.xM.sub.1-x)N, wherein M represents at least one kind of an element selected from the group consisting of Zr, Hf, V, Nb, Ta, Cr, Mo, W, Al, Si and Y, and x represents an atomic ratio of a Ti element based on a sum of the Ti element and an M element, and satisfies 0.45x0.9. Also, an average grain size of grains constituting the hard layer is 200 nm or more and 600 nm or less, and the grains of the hard layer satisfy predetermined conditions.