Provided is a cutting tool including a base material and a coating layer provided on the base material, the coating layer including a titanium carbonitride layer provided on the base material, an intermediate layer provided on the titanium carbonitride layer in contact therewith, and an alumina layer provided on the intermediate layer in contact therewith, the intermediate layer being composed of a compound made of titanium, carbon, oxygen, and nitrogen, the intermediate layer having a thickness of more than 1 μm, when P.sub.C1 atomic % represents an atomic ratio of the carbon in an interface between the intermediate layer and the alumina layer, and P.sub.C2 atomic % represents an atomic ratio of the carbon at a point A away from the interface by 1 μm on a side of the intermediate layer, a ratio P.sub.C1/P.sub.C2 of the P.sub.C1 to the P.sub.C2 being more than or equal to 1.03.

Provided is a cutting tool including a base material and a coating layer provided on the base material, the coating layer including a titanium carbonitride layer provided on the base material, an intermediate layer provided on the titanium carbonitride layer in contact therewith, and an alumina layer provided on the intermediate layer in contact therewith, the intermediate layer being composed of a compound made of titanium, carbon, oxygen, and nitrogen, the intermediate layer having a thickness of more than 1 μm, when P.sub.C1 atomic % represents an atomic ratio of the carbon in an interface between the intermediate layer and the alumina layer, and P.sub.C2 atomic % represents an atomic ratio of the carbon at a point A away from the interface by 1 μm on a side of the intermediate layer, a ratio P.sub.C1/P.sub.C2 of the P.sub.C1 to the P.sub.C2 being more than or equal to 1.03.

A coated cutting tool, comprising: a substrate; and a coating layer formed on a surface of the substrate, wherein the coating layer includes a lower layer and an upper layer in this order from a substrate side toward a surface side, and the upper layer is formed on a surface of the lower layer, the lower layer contains a compound having a composition represented by (Al.sub.xTi.sub.1-x)N, an average thickness of the lower layer is 1.0 μm or more and 15.0 μm or less, the upper layer contains an α-Al.sub.2O.sub.3 layer containing α-Al.sub.2O.sub.3, an average thickness of the upper layer is 0.5 μm or more and 15.0 μm or less, and in grains of the α-Al.sub.2O.sub.3 layer, a proportion of grains of which a grain size is 0.05 μm or more and less than 0.5 μm is 50% by area or more and 80% by area or less.

A coating includes a first base layer including a nitride of at least Al and Cr, a second base layer including a nitride of at least Al and Cr overlying the first base layer, and an outermost indicator layer overlying the second base layer. The first base layer has a positive residual compressive stress gradient. The second base layer has substantially constant residual compressive stresses. The outermost indicator layer includes a nitride of Si and Me, wherein Me is at least one of Ti, Zr, Hf, and Cr. The outermost indicator layer has residual compressive stresses that are less than the residual compressive stresses of the second base layer.

A coated tool in a non-limiting embodiment of the present disclosure includes a base and a coating film located on the base. The coated tool includes a first surface, a second surface adjacent to the first surface, and a cutting edge located on at least a part of a ridge part of the first surface and the second surface. The coating film includes an AlTiN film. The coating film has a first compressive stress σ11 in a first direction which is parallel to a surface of the base and intersects with the cutting edge at an angle of 90°, and a second compressive stress σ22 in a second direction which intersects with the first direction at an angle of 90°. The first compressive stress σ11 is different from the second compressive stress σ22.

A cutting tool may include a base member and a diamond layer located on the base member. The cutting tool may include a first surface, a second surface, and a cutting edge located in at least a part of a ridge line which the first surface intersects with the second surface. The diamond layer may be located in at least a part of the first surface, at least a part of the second surface, and at least a part of the cutting edge. A maximum height in the cutting edge may be smaller than a maximum height in the first surface. The maximum height in the cutting edge may be greater than a maximum height in the second surface.

A cutting tool may include a base member and a diamond layer located on the base member. The cutting tool may include a first surface, a second surface, and a cutting edge located in at least a part of a ridge line which the first surface intersects with the second surface. The diamond layer may be located in at least a part of the first surface, at least a part of the second surface, and at least a part of the cutting edge. A maximum height in the cutting edge may be smaller than a maximum height in the first surface. The maximum height in the cutting edge may be greater than a maximum height in the second surface.

A composite sintered material includes a plurality of diamond grains, a plurality of cubic boron nitride grains, and a remainder of a binder phase, wherein the binder phase includes cobalt, a content of the cubic boron nitride grains in the composite sintered material is more than or equal to 3 volume % and less than or equal to 40 volume %, and an average length of line segments extending across continuous cubic boron nitride grains in appropriately specified straight lines extending through the composite sintered material is less than or equal to a length three times as large as an average grain size of the cubic boron nitride grains.

The present invention includes an end mill body which is formed of ceramic, a chip discharge flute which is formed on an outer periphery of the end mill body, a peripheral cutting edge which is formed on an intersection ridge line between a wall surface facing a tool rotation direction in the chip discharge flute and an outer peripheral surface of the end mill body, an end cutting edge which is formed on an intersection ridge line between the wall surface in the chip discharge flute and a tip surface of the end mill body, and a corner cutting edge which is positioned at a tip outer-peripheral part of the end mill body, connects an outer end of the end cutting edge and a tip of the peripheral cutting edge to each other, and has a convexly curved shape which is convex toward a tip outer-peripheral side of the end mill body.

The present invention includes an end mill body which is formed of ceramic, a chip discharge flute which is formed on an outer periphery of the end mill body, a peripheral cutting edge which is formed on an intersection ridge line between a wall surface facing a tool rotation direction in the chip discharge flute and an outer peripheral surface of the end mill body, an end cutting edge which is formed on an intersection ridge line between the wall surface in the chip discharge flute and a tip surface of the end mill body, and a corner cutting edge which is positioned at a tip outer-peripheral part of the end mill body, connects an outer end of the end cutting edge and a tip of the peripheral cutting edge to each other, and has a convexly curved shape which is convex toward a tip outer-peripheral side of the end mill body.