Abstract: A cBN sintered material comprising cBN particles and a binder phase, in which the binder phase contains AlN and AlB2, a content proportion of cBN particles is 70 to 97 vol %, cBN sintered material has a volume resistivity up to 5×10?3 ?cm, a rate of a peak intensity derived from Al with respect to a peak intensity derived from cBN particles is less than 1.0%, cBN particles include fine particles and coarse particles, coarse particles optionally include ultra-coarse particles, with respect to the entire cBN particles, a content proportion ? of fine particles is from 10 vol %, a content proportion ? of coarse particles is from 30 vol %, a content proportion ? of ultra-coarse particles is 25 vol % or less, and a total of the content proportion ? of fine particles and the content proportion ? of coarse particles is 50 to 100 vol %.

Abstract: A cutting tool is rotatable about an axis line, and includes a main body portion, a cutting insert, and a plurality of anti-vibration members. The main body portion has an inner circumferential surface and an outer circumferential surface opposite to the inner circumferential surface. The cutting insert is attached to at least one of the inner circumferential surface and the outer circumferential surface. Each of the plurality of anti-vibration members is provided at the main body portion. Each of the plurality of anti-vibration members includes a weight member composed of a material having a specific gravity larger than a specific gravity of a material of the main body portion.

Abstract: A cubic boron nitride sintered material comprising cubic boron nitride grains, a binder phase, and a void, in which a percentage of the cubic boron nitride grains based on the total of the cubic boron nitride grains and the binder phase is 40 vol % to 70 vol %, a percentage of the binder phase based on the total of the cubic boron nitride grains and the binder phase is 30 vol % to 60 vol %, the binder phase includes 10 vol % to 100 vol % of aluminum oxide grains, an average grain size of the aluminum oxide grains is 50 to 250 nm, the cubic boron nitride sintered material comprises 0.001 vol % to 0.100 vol % of one or more first voids, and at least one portion of each of the first voids is in contact with the aluminum oxide grains.

Abstract: The cubic boron nitride sintered material is a cubic boron nitride sintered material comprising: cubic boron nitride particles in an amount of 70 vol % or more and less than 100 vol %, and a bonding material, wherein the bonding material includes an aluminum compound, and includes cobalt as a constituent element; the cubic boron nitride sintered material has a first region in which a space between adjacent cubic boron nitride particles is 0.1 nm or more and 10 nm or less; and when the first region is analyzed by using an energy dispersive X-ray analyzer equipped with a transmission electron microscope, the atom % of aluminum in the first region is 0.1 or more.

Abstract: A cutting tool includes a substrate and a coating film that is disposed on the substrate, wherein the coating film includes a first layer composed of metal tungsten and hexagonal ditungsten carbide, and the first layer has an elastic deformation rate of 43.0 or more and 58.0 or less.

Abstract: A drill has a first main body portion and a second main body portion. The first main body includes a chip discharging surface, a flank face, and an outer peripheral surface. A ridgeline between the chip discharging surface and the flank face constitutes a cutting edge. The chip discharging surface has an auxiliary flute surface provided in a form of a helix around a center axis, the auxiliary flute surface being contiguous to the cutting edge, the auxiliary flute surface being recessed in a direction opposite to a rotation direction of the drill. An auxiliary cutting edge portion has a first end portion and a second end portion. When viewed in a direction along the center axis, a value obtained by dividing the maximum value of the diameter of the second main body portion by the diameter of the first main body portion is 1.5 or more.

Abstract: A coolant supply mechanism is attachable to a cutting insert. The cutting insert has a first bottom surface, a first upper surface, and a first side surface. The first upper surface includes a corner portion that is located at a corner of the first upper surface when viewed in a plan view and that is contiguous to the first side surface so as to form a cutting edge, and a center portion located adjacent to the corner portion on a side opposite to the cutting edge when viewed in a plan view. The first upper surface is depressed toward the first bottom surface side at the center portion.

Abstract: A cutting tool including a base material and a hard layer provided on the base material, in which the hard layer is composed of a compound represented by TiaAlbBcN, an atomic ratio a is 0.25 or more and less than 0.55, an atomic ratio b of is 0.45 or more and less than 0.75, an atomic ratio c of is more than 0 and 0.1 or less, a sum of the atomic ratio a, the atomic ratio b and the atomic ratio c is 1, a ratio I(200)/I(002) of an intensity I(200) of an X-ray diffraction peak of a (200) plane to an intensity I(002) of an X-ray diffraction peak of a (002) plane in the hard layer is 2 to 10, and a full width at half maximum of the X-ray diffraction peak of the (002) plane is 2 degrees to 8 degrees.

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 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.

Abstract: The outer peripheral surface is provided with a first margin contiguous to each of the cutting edge and the flank face, and a second margin that is located on the rear side with respect to the first margin in a rotation direction and that is separated from each of the flank face and the thinning face. An outer peripheral portion of the first margin and an outer peripheral portion of the second margin have respective back tapers having the same angle. In a direction parallel to the axial line, a distance between a front end of the first margin and a front end of the second margin is more than or equal to 3 mm and less than or equal to 5 mm.

Abstract: A reamer is rotated about a central axis and has, in a direction along a central axis, a tool front end and a tool rear end that is an end opposite to the tool front end. The reamer includes a blade on a tool front end side. The blade has, on a circumferential surface, a chamfered cutting edge located on the tool front end side, a circumferential cutting edge contiguous to an end of the chamfered cutting edge on a tool rear end side, and a margin that is a surface contiguous to the circumferential cutting edge. The circumferential cutting edge includes a front end portion between a first position and a second position, the first position being an end on a chamfered cutting edge side, the second position having a distance of 1 mm from the first position in a direction of extension of the circumferential cutting edge.

Abstract: The boundary flow path is constituted of a pair of boundary wall surfaces facing each other in a first cross section intersecting each of the first flow path, the boundary flow path, and the second flow path. An inclination of a tangent to at least one of the pair of boundary wall surfaces is continuously changed. In a second cross section perpendicular to a direction in which coolant flows, a lateral width of the first flow path is larger than a longitudinal width of the first flow path and a lateral width of the second flow path is larger than a longitudinal width of the second flow path when a longitudinal direction represents a direction in which the pair of boundary wall surfaces face each other and a lateral direction represents a direction perpendicular to the longitudinal direction.

Abstract: A ridgeline between the thinning face and the flank face includes a first thinning portion contiguous to the outer cutting edge, and a second thinning portion contiguous to the first thinning portion. When viewed in a direction along the central axis, the first thinning portion is linear and the second thinning portion is curved. When viewed in the direction along the central axis, the first thinning portion, and a boundary between the first thinning portion and the second thinning portion are located rearward in a rotational direction relative to a first straight line, and are located forward in the rotational direction relative to a second straight line, the first straight line being a straight line passing through the central axis and parallel to the first thinning portion, and the second straight line being a straight line perpendicular to the first straight line.

Abstract: Provided is a cutting tool that can have a long tool life even when used to cut soft metals in particular. The cutting tool comprises a base body and a hard carbon film arranged on the base body, the hard carbon film includes an amorphous phase and a graphite phase, the density of the hard carbon film is no less than 2.5 g/cm3 and no more than 3.5 g/cm3, the degree of crystallinity of the hard carbon film is no more than 6.5%, and the average coordination number of the amorphous phase is no less than 2.5 and no more than 4.

Abstract: Provided is a cutting tool comprising a base body and a hard carbon film arranged on the base body, in which, when the cross section of the hard carbon film is observed using a high angle annular dark field scanning transmission electron microscope, the area proportion of black regions with an equivalent circle diameter of 10 nm or more is 0.7% or less, and the hard carbon film has a hydrogen content of 5 atom% or less.

Abstract: A cubic boron nitride sintered material includes: more than or equal to 20 volume % and less than 80 volume % of cubic boron nitride grains; and more than 20 volume % and less than or equal to 80 volume % of a binder phase, and when a carbon content is measured from a cubic boron nitride grain into the binder phase in a direction perpendicular to an interface between the cubic boron nitride grain and the binder phase using TEM-EDX, a first region having a carbon content larger than an average value of a carbon content of the binder phase exists, the interface exists in the first region, and a length of the first region is more than or equal to 0.1 nm and less than or equal to 10 nm.

Abstract: A cutting tool includes: a main body portion composed of a cemented carbide; and a front end portion composed of a binderless cubic boron nitride polycrystal, the front end portion being joined to the main body portion. In an axial direction along a rotation axis of the main body portion, the main body portion has a first end and a second end opposite to the first end. The front end portion has a neck portion and an edge portion, the neck portion protruding from the second end along the axial direction, the edge portion being continuous to the neck portion, the edge portion being located at a location distant away from the second end relative to the neck portion in the axial direction. In the axial direction, the neck portion has a third end on the edge portion side and a fourth end opposite to the third end.