A cutting tool includes a substrate and a diamond layer that covers the substrate. The diamond layer includes a rake face and a flank continuous to the rake face. A ridgeline between the rake face and the flank forms a cutting edge. The substrate includes a top surface opposed to the rake face. When viewed in a direction perpendicular to the top surface, the rake face includes a plurality of protrusions. In a cross-section perpendicular to a direction of extension of the cutting edge, each of the plurality of protrusions includes an inclined portion and a curvature portion continuous to the inclined portion. In the cross-section, a height of the inclined portion in the direction perpendicular to the top surface increases as a distance from the cutting edge increases.

A cubic boron nitride sintered material tool contains a plurality of cBN grains. cBN grains located on a surface of the cutting edge contain a cubic boron nitride phase, and a hexagonal boron nitride phase. When a ratio I.sub.π*/I.sub.σ* between an intensity of a π* peak derived from a π bond of hBN in the hexagonal boron nitride phase and an intensity of a σ* peak derived from a σ bond of hBN in the hexagonal boron nitride phase and a σ bond of cBN in the cubic boron nitride phase is determined by measuring an energy loss associated with excitation of K-shell electrons of boron, the ratio I.sub.π*/I.sub.σ* of the cBN grain on the surface of the cutting edge is 0.1 to 2, and the ratio I.sub.π*/I.sub.σ* of the cBN grain at a depth position of 5 μm from the surface of the cutting edge is 0.001 to 0.1.

Provided is an end mill which includes an end mill main body having a bottom blade having a convex hemispherical shape, and a hard coating film coated on at least a surface of a distal end portion of the end mill main body. A diameter D (mm) of the bottom blade is 2 mm or less. A ratio W/D of a width W (mm) of a chisel portion to the diameter D (mm) is within a range of 0.020 to 0.060. A ratio L/D of a facing length L (mm) of chip discharge grooves to the diameter D (mm) is within a range of 0.014 to 0.090. A rake angle of the bottom blade in a range in which a chisel edge is formed in the chisel portion is within a range of −15° to −30°.

In a diamond-coated tool provided with a blade which includes a base material and a diamond layer formed on the base material, when a length of the blade along an extending direction thereof is denoted by L, and a thickness of the diamond layer of the blade is measured at a total number of 11 points which are arranged from one end of the blade along the extending direction thereof and separated from each other at an interval of L/10, the thickness is the same at all of the 11 points, or a ratio d.sub.min/d.sub.max between a minimum value d.sub.min of the thickness and a maximum value d.sub.max of the thickness is 0.7 or more and less than 1.

A coated cutting tool is provided which allows for satisfactory machining over a long period of time, particularly in the machining of difficult-to-machine materials with low thermal conductivity. The coated cutting tool includes a substrate and a coating layer formed on a surface of the substrate, wherein: at least one layer of the coating layer comprises a predetermined layer containing a compound having a composition represented by the formula: (Al.sub.XTi.sub.1-X)N [wherein x denotes an atomic ratio of the Al element based on a total of the Al element and the Ti element, and x satisfies 0.60≤x≤0.85]; a value of an orientation index TC (311) of a cubic (311) plane of the predetermined layer is from 2.5 or more to 4.2 or less; and an average thickness of the predetermined layer is from 1.0 μm or more to 12.0 μm or less.

A coated tool according to the present disclosure includes a base member and a coating layer located on the base member. The coating layer includes a first peak located in a range of 0° to 90° and a second peak located at a higher angle side than the first peak in a distribution of X-ray intensity indicated at α axis of a pole figure, the X-ray intensity regarding a plane of the cubic crystal. The coating layer further includes a valley part between the first peak and the second peak, and the valley part includes the X-ray intensity smaller than the X-ray intensity at each of the first peak and the second peak.

A coated cutting tool comprises a substrate and a coating layer formed on a surface of the substrate, and has a rake face and a flank. The coating layer comprises an alternating laminate structure in which first compound layers containing AlN and second compound layers containing a compound are laminated in an alternating manner, the compound having a composition represented by formula (1) below:
(Ti.sub.1-xAl.sub.x)N  (1)
(wherein x satisfies 0.40≤x≤0.70). An average thickness T.sub.1 per first compound layer is 5 nm or more to 160 nm or less, and an average thickness T.sub.2 per second compound layer is 8 nm or more to 200 nm or less. A ratio of T.sub.1 to T.sub.2 is 0.10 or more to 0.80 or less. An average thickness T.sub.3 of the alternating laminate structure is 2.5 μm or more to 7.0 μm or less. A ratio (H/E) of hardness H to elastic modulus E is 0.065 or more to 0.085 or less at the rake face or the flank.

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.

In a surface-coated cutting tool in which a hard coating layer having a total layer thickness of 0.5 to 10 μm is deposited on a surface of a tool body made of WC-based cemented carbide or TiCN-based cermet, the hard coating layer has an alternately laminated structure of A layers and B layers, in a case where the A layer is: (Al.sub.aTi.sub.1-a)N (here, a is in atomic ratio), the A layer satisfies 0.50≦a<0.75, in a case where the B layer is: (Al.sub.bTi.sub.1-b)N (here, b is in atomic ratio), the B layer satisfies 0.75≦b≦0.95, and when a layer thickness per layer of the A layers is represented by x (nm) and a layer thickness per layer of the B layers is represented by y (nm), 5y≧x≧3y and 250 (nm)≧x+y≧100 (nm) are satisfied.