A cutting tool having a cutting edge member which forms at least one corner part, wherein a material for the cutting edge member is selected from either diamond, an ultrahigh-pressure sintered body containing cubic boron nitride or a PVD or CVD coating applied to a surface of the ultrahigh-pressure sintered body. At least part of an intersecting edge between an end surface of the cutting edge member and a peripheral side surface thereof is provided with a cutting edge. A chip breaker comprising a breaker wall surface is formed in the end surface of the cutting edge member. The breaker wall surface has at least one projected surface part which bulges outwardly from the cutting tool. As viewed from the end surface, the recessed surface part is arranged so as to be apart from a virtual plane A which is defined so as to divide the corner part into halves.

There are provided: a sintered material having an excellent wear resistance even under a high speed cutting condition; a tool using the sintered material; and a method of producing the sintered material. The sintered material includes: a first particle group including a particle having a cubic rock-salt structure represented by Al.sub.(1-x)Cr.sub.xN (formula (1)) (where x satisfies 0.2≦x≦0.8); and a second particle group including a particle of at least one first compound selected from a group consisting of oxide and oxynitride of aluminum, zirconium, yttrium, magnesium, and hafnium.

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 (0.4≦X≦0.7, X is an atomic ratio) with an average layer thickness of 0.5 to 10 μm, the (Ti, Al)N layer has a cubic crystal structure, and Ia−Ib<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.

In a drill, a negative hind is provided on a rake face, and a ridge line at an intersecting position of the negative land and a flank face, a ridge line at an intersecting position of the flank face and a margin, and a ridge line at an intersecting position of the negative land and the margin are convex faces in a longitudinal rectangular cross section. When a curvature radius of the convex face of a first ridge line at the intersecting position of the flank face and the negative land is 1, at curvature radius of the convex face of a second ridge line at the intersecting position of the flank face and the margin is 0.8 to 1.5 times the curvature radius of the first ridge line, and a curvature radius of the convex face of a fourth ridge line at the intersecting position of the negative land and the margin is 1.5 to 3.0 times the curvature radius of the first ridge line.

A coated cutting tool includes a substrate and a coating layer formed onto the surface of the substrate. The coating layer contains an outermost layer. The outermost layer contains NbN. The NbN contains cubic NbN and hexagonal NbN. When a peak intensity at a (200) plane of cubic NbN is made I.sub.c, a peak intensity at a (101) plane of the hexagonal NbN is made I.sub.h1, and a sum of peak intensities at a (103) plane and a (110) plane of the hexagonal NbN is made I.sub.h2 in X-ray diffraction analysis, a ratio [I.sub.h1/(I.sub.h1+I.sub.c)] of I.sub.h1 based on a sum of I.sub.c and I.sub.h1 is 0.5 or more and less than 1.0, and a ratio [I.sub.h1/(I.sub.h1+I.sub.h2)] of I.sub.h1 based on a sum of I.sub.h1 and I.sub.h2 is 0.5 or more and 1.0 or less.

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 0.45≦x≦0.9. 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.

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.

The present disclosure relates to a coated cutting tool including a substrate and a coating disposed on the substrate, wherein the coating includes a layer of Ti.sub.xZr.sub.yAl.sub.(1-x-y)N, where 0<x≦0.3, 0.2≦y≦0.8 and 0.1≦(1-x-y)≦0.7. The disclosure further relates to a method of producing such a coated cutting tool, and to a cutting insert forming a coated cutting tool.

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 0.3≤x≤0.7, and a second layer of (Ti1-p-qAlp Siq)N with 0.15≤p≤0.45, and 0.05≤q≤0.20, wherein the second layer is deposited outside the first layer as seen in a direction from the body.

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.