Abstract: 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 to the surface side of the coating layer, the lower layer comprises one or two or more specific Ti compound layers, the intermediate layer comprises an ?-Al2O3 layer, the upper layer comprises one or two or more specific Ti compound layers, at least one of the Ti compound layers in the upper layer is a TiCN layer, the average thickness of the upper layer is 1.00 ?m or more and 6.50 ?m or less, and the upper layer satisfies the conditions represented by the formula (i): 25?RSA1<70 and the formula (ii): 25?RSA2<70.

Abstract: A coated cutting tool comprising: a substrate and a coating layer, wherein the coating layer includes a lower layer and an upper layer; the lower layer includes one or two or more specific Ti compound layers; the upper layer includes an ?-type Al2O3 layer; an average thickness of the lower layer is 2.0 ?m to 15.0 ?m; an average thickness of the upper layer is 3.5 ?m to 15.0 ?m; in the upper layer, a ratio of a length of ?3 grain boundaries to a total length of 100% of a total grain boundary is more than 50% and 80% or less, and a ratio of the length of ?3 grain boundaries to a total length of 100% of CSL grain boundaries is 70% or more; and in the upper layer, a texture coefficient TC(0,0,12) of the ?-type Al2O3 layer is 8.0 or more and 8.9 or less.

Abstract: A covered cutting tool having a cemented carbide and a covering layer formed on the cemented carbide. The covered cutting tool includes a rake face, a flank face, and a cutting edge line part located between the rake face and the flank face. The coating layer includes a compound layer containing a compound having a composition represented by (AlxTi1-x)N. The average thickness T1 of the covering layer in the cutting edge line part and the average thickness T2 of the coating layer in the rake face at a position 2 mm or more away from the cutting edge line part toward the rake face are within specific ranges and satisfy T2<T1. The residual stress S1 of the cemented carbide in the cutting edge line part and the residual stress S2 of the cemented carbide in the rake face at a position 2 mm or more away from the cutting edge line part toward the rake face satisfy S2<S1.

Abstract: A coated cutting tool comprising: a substrate and a coating layer, wherein the coating layer includes a lower layer and an upper layer; the lower layer includes one or two or more specific Ti compound layers; the upper layer includes an ?-type Al2O3 layer; an average thickness of the lower layer is 2.0 ?m to 15.0 ?m; an average thickness of the upper layer is 3.5 ?m to 15.0 ?m; in the upper layer, a ratio of a length of ?3 grain boundaries to a total length of 100% of a total grain boundary is more than 50% and 80% or less, and a ratio of the length of ?3 grain boundaries to a total length of 100% of CSL grain boundaries is 70% or more; and in the upper layer, a texture coefficient TC(0,0,12) of the ?-type Al2O3 layer is 8.0 or more and 8.9 or less.

Abstract: Provided is a coated cutting tool of long tool life and that affords superior machined surface quality. A coated cutting tool includes a substrate, and a coating layer formed on the substrate. The coated cutting tool includes at least one flank face, at least one rake face, and a honing section rounded and connecting the flank face and the rake face. The coating layer includes a lower layer, an intermediate layer and an upper layer, in this order from the side of the substrate. The lower layer is composed of one, or two or more Ti compound layers made up of a Ti compound of Ti and at least one element selected from the group consisting of C, N, O and B. The intermediate layer contains ?-type Al2O3. The upper layer contains a compound represented by following formula (1): Ti(C1-x-yNxOy) (1). An average thickness of the coating layer on the flank face side is 5.0 ?m more and 30.0 ?m or less.

Abstract: [Problem] To provide a coated cutting tool having excellent fracture resistance and thus allowing for the extension of tool life. [Means for Resolution] A covered cutting tool having a cemented carbide and a covering layer formed on the cemented carbide. The covered cutting tool includes a rake face, a flank face, and a cutting edge line part located between the rake face and the flank face. The coating layer includes a compound layer containing a compound having a composition represented by (AlxTi1-x)N. The average thickness T1 of the covering layer in the cutting edge line part and the average thickness T2 of the coating layer in the rake face at a position 2 mm or more away from the cutting edge line part toward the rake face are within specific ranges and satisfy T2 <T1.

Abstract: Provided is a coated cutting tool of long tool life and that affords superior machined surface quality. A coated cutting tool includes a substrate, and a coating layer formed on the substrate. The coated cutting tool includes at least one flank face, at least one rake face, and a honing section rounded and connecting the flank face and the rake face. The coating layer includes a lower layer, an intermediate layer and an upper layer, in this order from the side of the substrate. The lower layer is composed of one, or two or more Ti compound layers made up of a Ti compound of Ti and at least one element selected from the group consisting of C, N, O and B. The intermediate layer contains ?-type Al2O3. The upper layer contains a compound represented by following formula (1): Ti(C1-x-yNxOy) (1). An average thickness of the coating layer on the flank face side is 5.0 ?m more and 30.0 ?m or less.

Abstract: 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 (TixM1-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.

Abstract: 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 (TixM1-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.