Abstract: A first main trajectory represents a trajectory of a first main cutting edge obtained by revolving and projecting the first main cutting edge onto a plane including a central axis. A second main trajectory represents a trajectory of the second main cutting edge obtained by revolving and projecting the second main cutting edge onto the plane. The first main trajectory intersects the second main trajectory. A tangent to the first main trajectory at an intersection between the first main trajectory and the second main trajectory is inclined to be closer to the central axis in a direction from the first surface toward the second surface. A tangent to the second main trajectory at the intersection is inclined to be closer to the central axis in a direction from the second surface toward the first surface.

Abstract: A single-crystal diamond having a first facet plane is prepared. The single-crystal diamond is fixed to the support based on the first facet plane. An X-ray image of the single-crystal diamond is captured, the X-ray image being an X-ray image in which a crystal orientation of the single-crystal diamond is associated with an X-ray emission direction by associating the support to which the single-crystal diamond is fixed with the X-ray emission direction. A position of an inclusion of the single-crystal diamond in the single-crystal diamond is specified based on the X-ray image. It is determined whether or not a shape of the diamond tool intermediate is extractable from the single-crystal diamond with the inclusion being not included in an inclusion-excluded region. The shape of the diamond tool intermediate is extracted from the single-crystal diamond with the inclusion being not included in the inclusion-excluded region.

Abstract: A surface-coated cutting tool includes a base material and a coating film formed on a surface of the base material. The coating film includes a first alternating layer and a second alternating layer formed on the first alternating layer. The first alternating layer includes first and second layers. The second alternating layer includes third and fourth layers. One or a plurality of the first layers and one or a plurality of the second layers are layered alternately, and one or a plurality of the third layers and one or a plurality of the fourth layers are layered alternately.

Abstract: A cutting tool includes a rake face, a flank face, and a cutting edge ridge line connecting the rake face and the flank face. A portion of the rake face and a portion of the flank face adjacent to the cutting edge ridge line are made of a diamond sintered body including diamond grains. A dislocation density in the portion of the flank face is 8×1015/m2 or less. The diamond grains have an average grain size of 0.1 ?m to 50 ?m. A content ratio of the diamond grains in the diamond sintered body is 80% by volume to 99% by volume.

Abstract: A cutting tool comprising a base material and a coating, wherein the coating includes a first layer having a multilayer structure in which a first unit layer and a second unit layer are alternately stacked; a thickness of the first unit layer is 2 to 50 nm; a thickness of the second unit layer is 2 to 50 nm; a thickness of the first layer is 1.0 ?m or more and 20 ?m or less, the first unit layer is composed of TiaAlbBcN, and the second unit layer is composed of TidAleBfN, wherein 0.49?a?0.70, 0.19?0.40, 0.10<c?0.20, a+b+c=1.00, 0.39?d?0.60, 0.29?e?0.50, 0.10<f?0.20, d+e+f=1.00, 0.05?a?d?0.20, and 0.05?e?b?0.20 are satisfied, and a percentage of the number of atoms of titanium to the total number of atoms of titanium, aluminum and boron is 45% or more in the first layer.

Abstract: A cutting tool comprising a base material and a coating, wherein the coating includes a first layer having a multilayer structure in which a first unit layer and a second unit layer; a thickness of the first unit layer is 2 nm or more and less than 50 nm; a thickness of the second unit layer is 2 nm or more and less than 50 nm; a thickness of the first layer is 1.0 ?m or more and 20 ?m or less, the first unit layer is TiaAlbBcN, and the second unit layer is TidAleBfN, wherein 0.54?a?0.75, 0.24?b?0.45, 0<c?0.10, a+b+c=1.00, 0.44?d?0.65, -.34?e?0.55, 0<f?0.10, d+e+f=1.00, 0.05?a?d?0.20, and 0.05?e?b?0.20 are satisfied, and a percentage of the number of atoms of titanium to the total number of atoms of titanium, aluminum and boron is 50% or more in the first layer.

Abstract: A polycrystalline cubic boron nitride comprising 99.5% by volume or more of cubic boron nitride, wherein the polycrystalline cubic boron nitride has a heat conductivity of 300 W/mK or more, the polycrystalline cubic boron nitride has a carbon content of 100 ppm or more and 1000 ppm or less in terms of mass, the polycrystalline cubic boron nitride comprises a plurality of crystal grains, and the plurality of crystal grains have a median diameter d50 of an equivalent circle diameter of 0.9 ?m or more and 10 ?m or less.

Abstract: A cutting tool includes a substrate and a hard layer, wherein the hard layer includes a first unit layer and a second unit layer being alternately layered in the hard layer, a thickness of the first unit layer is 2 to 100 nm, a thickness of the second unit layer is 2 to 100 nm, the first unit layer is composed of TiaAlbBcN, the second unit layer is composed TidAleBfN, an atomic ratio a satisfy 0.25?a<0.45, an atomic ratio b satisfy 0.55?b<0.75, an atomic ratio c satisfy 0<c?0.1, a total of the atomic ratios a, b and c is 1, an atomic ratio d satisfy 0.35?d<0.55, an atomic ratio e satisfy 0.45?e<0.65, an atomic ratio f satisfy 0<f?0.1, a total of the atomic ratios d, e and f is 1, the atomic ratios a and d satisfy 0.05?d?a?0.2, and the atomic ratios b and e satisfy 0.05?b?e?0.2.

Abstract: A diamond sintered material includes diamond grains, wherein a content ratio of the diamond grains is more than or equal to 80 volume % and less than or equal to 99 volume % with respect to the diamond sintered material, an average grain size of the diamond grains is more than or equal to 0.1 ?m and less than or equal to 50 ?m, and a dislocation density of the diamond grains is more than or equal to 8.1×1013 m?2 and less than 1.0×1016 m?2.

Abstract: A cutting tool, including a cutting edge portion composed of a cubic boron nitride sintered material, wherein the cutting edge portion has: a flank face; a rake face contiguous to the flank face; and a cutting edge positioned on a ridgeline of the flank face and the rake face, an arithmetical mean height Sa of the flank face is 0.5 ?m or more and 3.0 ?m or less, the Sa is measured in accordance with ISO25178-2:2012, and an oxygen concentration of the flank face is 10 mass % or more and 50 mass % or less.

Abstract: A cutting tool comprising a substrate and a coating film disposed on the substrate, wherein the coating film comprises a first layer; the first layer has a thickness of 0.2 ?m or more and 9 ?m or less; the first layer is composed of Ti(1-x-y)AlxMyN, wherein M is at least one element such as zirconium; in the first layer, x and y change along the thickness direction of the first layer; a maximum value of x, xmax, is 0.20 or more and 0.70 or less; a minimum value of x, xmin, is 0 or more and 0.6 or less; xmax and xmin satisfy 0.01?xmax?xmin?0.7; a maximum value of y, ymax, is 0.01 or more and 0.20 or less; a minimum value of y, ymin, is 0 or more and 0.19 or less; and ymax and ymin satisfy 0.01?ymax?ymin?0.2.

Abstract: A rotary cutting tool according to the present disclosure is rotatable about an axial line and includes a rake face and a flank face. The flank face is contiguous to the rake face. A ridgeline between the rake face and the flank face constitutes a cutting edge. In a cross section perpendicular to the axial line, the rake face is constituted of a plurality of straight line portions.

Abstract: A cubic boron nitride sintered material includes: more than or equal to 80 volume % and less than or equal to 96 volume % of cubic boron nitride grains; and a binder, wherein the binder includes tungsten carbide, cobalt, and an aluminum compound, and Ha/Hb?0.40 is satisfied, where Hb represents a hardness of the cubic boron nitride sintered material and Ha represents a hardness of the cubic boron nitride sintered material after performing acid treatment onto the cubic boron nitride sintered material to substantially remove the binder in the cubic boron nitride sintered material.