In a hard-film-coated drill having a cemented carbide drill body coated with a hard film, the drill body is provided with a smooth region at a boundary between a flank surface and a rake surface. The surface hardness of the hard film is within 2000 to 2500 HV in Vickers hardness. A radius r1 (μam) of curvature of the first ridgeline L1 where the smooth region and the flank surface intersect is represented by r1=0.45×D+a1 (10≤a1≤25), where D is the diameter (mm) of the body. A radius r2 (μm) of curvature the second ridgeline L2 where the flank surface and a margin intersect is represented by r2=0.65×D+a2 (39≤a2≤67). A thickness t1 (μm) of the hard film is represented by t1=0.8×ln(D)+a3 (0.7≤a3≤3.0).

The present disclosure relates to a cutting tool including a cemented carbide substrate having WC, gamma phase and a binder phase. The substrate is provided with a binder phase enriched surface zone, which is depleted of gamma phase, wherein no graphite and no ETA phase is present in the microstructure and wherein the binder phase is a high entropy alloy.

An insert based on an aspect includes a first face, a second face located opposite to the first face, a third face located between the first face and the second face, and a cutting edge located on an intersection of the first face and the third face. The first face includes a first region inclined so as be close to the second face as being separated away from the cutting edge. A virtual straight line orthogonal to the cutting edge is set as a first virtual straight line in a front view of the first face. A ten-point average of roughness the first region in a direction along the first virtual straight line is expressed by Rz1a and a ten-point average of roughness of the first region in a direction along the cutting edge is expressed by Rz1b, and Rz1a is larger than Rz1b.

A cutting tool made of a cemented carbide substrate of WC, a metallic binder phase and gamma phase is provided. The cemented carbide has a well distributed gamma phase and a reduced amount of abnormal WC grains. The cutting tool has a more predicted tool life and an increased resistance against plastic deformation.

A coated cutting tool of a cemented carbide substrate made of WC, a metallic binder phase and a gamma phase has a well distributed gamma phase and a reduced amount of abnormal WC grains. Further, the coated cutting tool is provided with a CVD coating of TiCN and an α-Al.sub.2O.sub.3 layer, wherein the α-Al.sub.2O.sub.3 layer exhibits a texture coefficient TC(0 0 12)≥7.2 and wherein in the ratio I(0 0 12)/I(0 1 14)≥1. The coated cutting tool has an increased resistance against plastic deformation. whilst maintaining toughness.

A cutting insert based on a non-limiting aspect has a first member and a second member joined to the first member. The second member has an upper surface and a side surface adjacent to the upper surface. The upper surface includes a first side, a second side and a corner. The upper surface has a first convex portion extending toward the corner, and a second convex portion extending from the first convex portion toward the first side. The second convex portion has a first end portion and a second end portion located closer to the corner than the first end portion. A first length from the first end to the first side is less than a second length from the second end portion to the first side in a top view.

A coated cutting tool according to the present invention is 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 formed on a surface of the lower layer, and an upper layer formed on a surface of the intermediate layer; the lower layer is a predetermined Ti compound layer with a predetermined average thickness; the intermediate layer is an α-type aluminum oxide layer with a predetermined average thickness; the upper layer is a Ti carbonitride layer with a predetermined average thickness; and a texture coefficient of a predetermined plane of each of the α-type aluminum oxide layer and the Ti carbonitride layer falls within a predetermined range.

A surface-coated cutting tool includes a substrate composed of cemented carbide and a coating film. The coating film includes an intermediate layer in contact with the substrate and an upper layer formed on the intermediate layer. The upper layer is made up of a single layer consisting of an upper base layer which is a layer in contact with the intermediate layer or multiple layers constituted of two or more layers. A mismatch in lattice interplanar spacing in an interface region between the substrate and the intermediate layer is not higher than 65% of a theoretical value of a mismatch in lattice interplanar spacing between the substrate and the upper base layer. A mismatch in lattice interplanar spacing in an interface region between the intermediate layer and the upper base layer is not higher than 65% of the theoretical value of the mismatch in lattice interplanar spacing between the substrate and the upper base layer.

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 including at least one Ti compound layer containing a specific Ti compound, an intermediate layer including an α-type Al.sub.2O.sub.3 layer containing α-type Al.sub.2O.sub.3, and an upper layer including a TiCN layer containing TiCN; the respective layers are laminated in this order from the substrate side toward a surface side of the coating layer; an average thickness of the coating layer is from 5.0 μm or more to 30.0 μm or less; and an angle formed by a normal to a cross-sectional surface which is located within a predetermined range below a surface of the intermediate layer and is parallel to the surface of the substrate and a normal to a (001) plane of a particle of an α-type Al.sub.2O.sub.3 layer, and an angle formed by a normal to a cross-sectional surface which is located within a predetermined range below a surface of the upper layer and is parallel to the surface of the substrate and a normal to a (111) plane of a particle of a TiCN layer, respectively satisfy predetermined conditions.

A hard coating film of a coated cutting tool contains Al within a range of 70 at % to 80 at % and Ti within a range of 20 at % to 30 at % with respect to a total amount of metallic (including metalloid) elements, and contains Ar of 0.50 at % or less with respect to a total amount of the metallic elements (including metalloid) and nonmetallic elements. The film has a diffraction peak due to each of a TiN (111) plane, a TiN (200) plane, and a TiN (220) plane of an fcc structure and an AlN (100) plane and an AlN (002) plane of a hcp structure, in which the diffraction peak of the TiN (200) plane indicates a maximum intensity and an intensity of the diffraction peak due to the TiN (111) plane is next thereafter. The average crystal grain size is within a range of 5 nm to 50 nm.