Abstract: A ball-end mill includes arcuate cutting edges each extending from a tip end to a peripherally outermost point along a S shape curve when viewed from the front side, spirally-shaped, peripheral cutting edges each smoothly connected to each arcuate cutting edge, and a convex rake face of each arcuate cutting edge protruding forward in a rotation direction. Each arcuate cutting edge has a radial rake angle satisfying ?<???, where ? is a radial rake angle at a radial angle of 5°, ? is a radial rake angle at a radial angle of 90°, and ? is a radial rake angle at a rotationally most projecting point of the arcuate cutting edge. The radial rake angle has the maximum value at a radial angle in a range of 12-40° and continuously decreases in a range from the rotationally most projecting point to the peripherally outermost point.

Abstract: An exchangeable tip cutting tool in which breakage of the threaded section and breakage of the thread ridges during installation of the machining head and under increased cutting load during cutting are limited and which is capable of performing machining with high efficiency; and a machining head and a holder to be used in the exchangeable tip cutting tool.

Abstract: Ceramic end mill with cutting edge portion including gashes between cutting edges and adjacent in a rotation direction. Center cut edges are formed at end cutting edges close to and facing rotation axis O. Center grooves are formed on rear sides of center cut edges and end cutting edges in the rotation direction continuous with a radial direction. The center grooves are continuous with positions where end cutting edge second surfaces face or approach rotation axis O. End cutting edge second surfaces are laid between center cut edges and end cutting edges. Center grooves are formed between end cutting edge second surfaces and center cut edges positioned on a rear side of end cutting edge second surfaces in the rotation direction. The center grooves pass on rotation axis O. Center grooves double as rake faces of the respective center cut edges and are continuous with the gashes.

Abstract: An embodiment of the invention provides a coated cutting tool having a base material and a hard coating, in which: the hard coating is formed from a nitride or a carbonitride having an Al content of from 50 at. % to 68 at. %, a Cr content of from 20 at. % to 46 at. %, and an Si content of from 4 at. % to 15 at. %, relative to the total amount of metal (including semimetal) elements, and when the total of metal (including semimetal) elements, nitrogen, oxygen, and carbon is designated as 100 at. %, the atomic percentage (at. %) A of metal (including semimetal) elements and the atomic percentage (at. %) B of nitrogen satisfy the relationship 1.03?B/A?1.07; and, in an intensity profile obtained from an X-ray diffraction pattern or a selected area diffraction pattern of a transmission electron microscope, an intensity of a peak from the (200) plane or the (111) plane of a face-centered cubic lattice structure exhibits the maximum intensity.

Abstract: An arc-ion-plated hard coating having a composition represented by (AlxTiyWz)aN(1-a-b)Ob, wherein x, y, z, a and b are numbers meeting by atomic ratio 0.6?x?0.8, 0.05?y?0.38, 0.02?z?0.2, x+y+z=1, 0.2?a?0.8, and 0.02?b?0.10), and having W—O bonds with substantially no Al—O bonds when identified by X-ray photoelectron spectroscopy, and having only a NaCl-type structure in an X-ray diffraction pattern.

Abstract: A multi-flute endmill including a cutting edge part having multiple cutting edges and flutes formed between adjacent cutting edges in a rotation direction around the tool axis O. A rake face of each cutting edge is formed from a rake face of an end cutting edge from the tool axis O side to the outer peripheral side of a shank, an adjacent rake face of a corner R edge that forms a surface different from the rake face of the end cutting edge, and an adjacent rake face of a peripheral cutting edge that forms a surface different from the rake face of the corner R edge. A gash is formed between the rake face of the end cutting edge and a flank of an end cutting edge that is adjacent on a forward side thereof in the rotation direction R.

Abstract: Multi-flute endmill having a cutting edge rake face formed from a side of a rotation axis to a peripheral side in a radial direction, and having an end cutting edge rake face. A peripheral cutting edge rake face adjacent to the end cutting edge rake face forms a face different from the end cutting edge rake face and serves as the rake face of a corner edge. An intersection between a convex ridge line is located in a boundary between the rake faces of the end cutting edge and peripheral cutting edge. A convex ridge line is located in a boundary between the end cutting edge rake face and a bottom surface of the flute is moved into the side of the rotation axis in the radial direction with respect to a boundary between the flank face of a corner edge and the flank face of the end cutting edge.

Abstract: A substantially parallelogramatic insert having a downward inclined main cutting edge and an auxiliary cutting edge in part of a long-side ridgeline and a short-side ridgeline adjacent to a pair of corner cutting edges of an upper surface; the main cutting edge being constituted by first to third straight cutting edges; the first to third straight cutting edges being connected in a bent-line shape with inward obtuse crossing angles when viewed from above, such that the second straight cutting edge is positioned outermost; and cutting edge angles ?1, ?2, ?3 between the rake faces and flanks of the first to third straight cutting edges meeting the relation of ?1>?2>?3.

Abstract: A hard-coated tool comprising a titanium carbonitride layer formed directly on a WC-based cemented carbide substrate by a chemical vapor deposition method; the titanium carbonitride layer having a composition comprising 74-81% by mass of titanium, 13-16% by mass of carbon and 6-10% by mass of nitrogen; the titanium carbonitride layer having a structure comprising columnar crystal grains having an average transverse cross section diameter of 0.01-0.22 ?m; a layer of W diffused from the substrate to the titanium carbonitride layer having an average thickness of 30-200 nm; and the titanium carbonitride layer having an X-ray diffraction peak of a (422) plane in a 2? range of 122.7-123.7°.

Abstract: A negative cutting insert having a cutting edge comprising four long-side cutting edge portions for rough cutting and four short-side cutting edge portions for finish cutting, which are connected alternately, thereby being able to conduct rough cutting when attached to a rough-cutting tool body, and finish cutting when attached to a finish-cutting tool body. When such cutting inserts are used for rough or finish cutting and then reattached to a finish-cutting tool body or a rough-cutting tool body, finish or rough cutting can be conducted, thereby using all cutting edges thoroughly.

Abstract: The ion bombardment of Cr, etc. onto a surface of a WC-based cemented carbide substrate in a nitrogen-based gas forms a modified phase having a bcc structure on the substrate surface, and a hard coating containing at least Cr formed thereon has high adhesion to the substrate by the modified phase.

Abstract: Radius mill and cutting work method that includes a plurality of end cutting edges arrayed around a central axis O and a plurality of arc-shaped radius end cutting edges continuous with the end cutting edges on an outer peripheral side in a radial direction. The end cutting edge is divided into an inner peripheral side end cutting edge and an outer peripheral side end cutting edge in a radial direction. Second surfaces of the plurality of inner peripheral side end cutting edges are coupled at a part close to the axis O. A region of coupled second surfaces is continuous from a region including the axis O to outer peripheral sides of respective inner peripheral side end cutting edges in a radial direction in a strip shape. A width of the strip-shaped region gradually enlarges from axis O side to an outer peripheral side in a radial direction.

Abstract: The present invention relates to an end mill, which comprises a bottom edge, which is composed of an arc-shaped cutting edge that is curved when seen from a direction perpendicular to the tool axis and a linear or curved medium-to-low inclination cutting edge, and a peripheral edge, wherein, when seen from a direction parallel to the tool axis, the arc-shaped cutting edge and a rim at the rearward side of the rotation at a flank of the arc-shaped cutting edge are curved with radii of curvatures, and the radius of curvature of the arc-shaped cutting edge is smaller than the radius of curvature of the rim at the rearward side of the rotation at the flank of the arc-shaped cutting edge.

Abstract: An insert detachably attached to an indexable rotary cutting tool, comprising an upper surface having cutting edges along the ridgeline, a lower surface, side surfaces, and a center hole for a fastening screw; each cutting edge comprising a corner cutting edge formed in each acute corner portion, and a bottom cutting edge and a peripheral cutting edge formed along the ridgelines on both sides of the corner cutting edge; the bottom cutting edge and the peripheral cutting edge having different clearance angles; a flank of the corner cutting edge comprising an angle-changing surface portion having a clearance angle continuously changing in a region from the bottom cutting edge to the peripheral cutting edge; and the length of the peripheral cutting edge being restricted by a receding portion adjacent to an upper end of the peripheral cutting edge.

Abstract: A multi-flute ball end mill comprising a shank portion, a cutting edge portion having a ball-shaped tip portion, and 3 or more cutting edges formed in the cutting edge portion; each cutting edge being constituted by a peripheral cutting edge having a twist angle ? of 35-45°, and a ball-end cutting edge having a twist angle ? at the outermost peripheral point, the twist angle ? and the twist angle ? meeting the relation of ????7°, such that the ball-end cutting edge is smoothly connected to the peripheral cutting edge; the ball-end cutting edge having a radial rake angle of ?37° to ?11°; the peripheral cutting edge having a radial rake angle of 2-8°; and a center-lowered, inclined cutting edge integrally extending from a tip end of each ball-end cutting edge to a rotation center point, in a tip end portion of the ball portion near the rotation center point.

Abstract: An indexable ball end mill comprising first to third inserts having arcuate cutting edges detachably attached with first to third screws to first to third seats in a semispherical tip end portion of a tool body; a first threaded hole for the first screw slantingly penetrating a slit-shaped first seat; the first insert having an inclined hole to avoid interference between the first screw and the second and third screws; a hole of the first insert and the first screw having at least partially finished surfaces, so that when the first screw penetrates the first insert attached to the first seat, the first insert is precisely positioned by tight engagement of both finished surfaces.

Abstract: A milling insert includes a polygonal tubular insert body which has: rake faces on one polygonal surface thereof, flanks composed of circumferential surfaces adjacent to the polygonal surface, and cutting edges defining a ridge line where the rake faces and flanks intersect each other as cutting edges. The rake faces have serrations where mount portions and valley portions are arrayed alternately to intersect the cutting edges. The ridge line has a waveform shape when the flanks are viewed from above. Bottom portions and top portions of the waveform are formed into concave circular arc portions and convex circular arc portions, respectively, and are alternately repeated. Both of the concave and convex circular arc portions are a ¼ circular arc or more to a ? circular arc or less. Each of the concave circular arc portions is unevenly located between the convex circular arc portions adjacent thereto.

Abstract: A hard-coated member comprising a substrate made of cemented carbide or high-speed steel and a titanium carbonitride layer formed on the substrate by a chemical vapor deposition method, the titanium carbonitride layer comprising first to third layers each having a columnar crystal structure in this order from the side of the substrate, the second layer being smaller than the first layer in carbon concentration, and the third layer being smaller than the second layer in carbon concentration, and an indexable rotary tool comprising it. The first layer is formed by using a starting material gas comprising a TiCl4 gas, an N2 gas, a C2-C5 hydrocarbon gas and an H2 gas, the second layer is formed by using a starting material gas comprising a TiCl4 gas, an N2 gas, an organic cyanide gas, a C2-C5 hydrocarbon gas, and an H2 gas, and the third layer is formed by using a starting material gas comprising a TiCl4 gas, an N2 gas, an organic cyanide gas, whose amount is smaller than in the second layer, and an H2 gas.

Abstract: A ball-end mill includes arcuate cutting edges each extending from a tip end to a peripherally outermost point along a S shape curve when viewed from the front side, spirally-shaped, peripheral cutting edges each smoothly connected to each arcuate cutting edge, and a convex rake face of each arcuate cutting edge protruding forward in a rotation direction. Each arcuate cutting edge has a radial rake angle satisfying ?<???, where ? is a radial rake angle at a radial angle of 5°, ? is a radial rake angle at a radial angle of 90°, and ? is a radial rake angle at a rotationally most projecting point of the arcuate cutting edge. The radial rake angle has the maximum value at a radial angle in a range of 12-40° and continuously decreases in a range from the rotationally most projecting point to the peripherally outermost point.

Abstract: A hard-coated tool comprising a titanium carbonitride layer formed directly on a WC-based cemented carbide substrate by a chemical vapor deposition method; the titanium carbonitride layer having a composition comprising 74-81% by mass of titanium, 13-16% by mass of carbon and 6-10% by mass of nitrogen; the titanium carbonitride layer having a structure comprising columnar crystal grains having an average transverse cross section diameter of 0.01-0.22 ?m; a layer of W diffused from the substrate to the titanium carbonitride layer having an average thickness of 30-200 nm; and the titanium carbonitride layer having an X-ray diffraction peak of a (422) plane in a 2? range of 122.7-123.7°.