A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein: the coating layer comprises a lower layer, an intermediate layer, and an upper layer in this order from the substrate side; the lower layer comprises one or two or more Ti compound layers containing a Ti compound of Ti and an element of at least one kind selected from the group consisting of C, N, O and B, the intermediate layer comprises an α-Al.sub.2O.sub.3 layer containing α-Al.sub.2O.sub.3, and the upper layer comprises a TiCNO layer containing TiCNO; an average thickness of the coating layer is 5.0 μm or more and 30.0 μm or less; in a specific first cross section, a misorientation A satisfies a specific condition; and in a specific second cross section, a misorientation B satisfies a specific condition.

A coated cutting tool comprising a substrate and a coating layer formed on a surface of the substrate, wherein the coating layer includes a predetermined lower layer, an intermediate layer comprising α-Al.sub.2O.sub.3, and an upper layer comprising TiCN; the lower layer, intermediate layer, and upper layer have predetermined average thicknesses; a condition represented by formula (1) [RSA≥40 (1)] is satisfied; the interface of the intermediate layer on the upper layer side has a kurtosis roughness (S.sub.ku) of more than 3.0; the interface of the intermediate layer on the upper layer side has a skewness roughness (S.sub.sk) of less than 0; and a condition represented by formula (2) [RSB≥40 (2)] is satisfied.

A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.4 or more and less than 0.55, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 10 nm or more and 45 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 20 nm to 50 nm, a maximum value of 40 nm to 60 nm, and a minimum value of 10 nm to 30 nm.

A surface-coated cutting tool includes a lower layer including a Ti compound layer, an intermediate layer including an α-Al.sub.2O.sub.3 layer, and an upper layer including a Zr-containing α-Al.sub.2O.sub.3 layer. The outermost layer of the lower layer contains 0.5 to 3 at % of oxygen. The frequencies of inclination angles between a normal line to a (0001) plane of Al.sub.2O.sub.3 grains of the intermediate layer and a normal line to a surface of a tool body have a highest peak in an inclination angle division of 0 to 10°. The ratio of the frequencies is 50 to 70%. The frequencies between the normal line to the (0001) plane of Al.sub.2O.sub.3 grains of the entirety of the intermediate and the upper layers and the normal line to the tool body surface have a highest peak in an inclination angle division of 0 to 10°. The ratio of the frequencies is 75% or more.

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.

A coated cutting tool includes a substrate of cemented carbide, cermet, ceramics, steel or cubic boron nitride, a multi-layered wear resistant coating and at least two refractory coating layers deposited. The at least two refractory coating layers include a first coating layer and a second coating layer deposited on top of each other. The first coating layer is titanium aluminium nitride or carbonitride Ti.sub.1-uAl.sub.uC.sub.vN.sub.w, with 0.2≦u≦1.0, 0≦v≦0.25 and 0.7≦w≦1.15 deposited by CVD. The second coating layer is titanium carbonitride Ti.sub.xC.sub.yN.sub.1-y, with 0.85≦x≦1.1 and 0.4≦y≦0.85, and is deposited on top of the first coating layer by MT-CVD. The second Ti.sub.xC.sub.yN.sub.1-y coating layer has a columnar grain morphology and the overall fiber texture of the Ti.sub.xC.sub.yN.sub.1-y coating layer is characterized by a texture coefficient TC (1 1 1)>2.

A coated tool is, for example, a cutting tool which is provided with a base material and a coating layer located on the base material, wherein a cutting edge and a flank surface are located on the coating layer, the coating layer has a portion in which at least a titanium carbonitride layer and an aluminum oxide layer having an a-type crystal structure are laminated in this order, and, with regard to a texture coefficient (Tc) (hkl) which is calculated on a basis of a peak of the aluminum oxide layer analyzed by an X-ray diffraction analysis, a texture coefficient (Tc1) (146) as measured from a surface side of the aluminum oxide layer in the flank surface is 1 or more.

A cutting tool comprises a substrate and a coating layer provided on the substrate, the coating layer including a multilayer structure layer composed of a first unit layer and a second unit layer, and a lone layer, the lone layer including cubic Ti.sub.zAl.sub.1-zN crystal grains, an atomic ratio z of Ti in the Ti.sub.zAl.sub.1-zN being 0.4 or more and less than 0.55, the lone layer having a thickness with an average value of 2.5 nm or more and 10 nm or less, the multilayer structure layer having a thickness with an average value of 40 nm or more and 95 nm or less, one multilayer structure layer and one lone layer forming a repetitive unit having a thickness with an average value of 50 nm to 100 nm, a maximum value of 90 nm to 110 nm, and a minimum value of 40 nm to 60 nm.

A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25≦n/N≦0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.

A cutting tool comprises a rake face and a flank face, the cutting tool being composed of a substrate made of a cubic boron nitride sintered material and a coating provided on the substrate, the coating including a MAlN layer, the MAlN layer including crystal grains of M.sub.xAl.sub.1-xN in the cubic crystal system, n.sub.F<n.sub.R being satisfied, where n.sub.F represents a number of voids per 100 μm in length of the MAlN layer on the flank face in a cross section of the MAlN layer, and n.sub.R represents a number of voids per 100 μm in length of the MAlN layer on the rake face in a cross section of the MAlN layer, n.sub.D being 3 or less, where n.sub.D represents a number of droplets per 100 μm in length of the MAlN layer on the flank face in a cross section of the MAlN layer.