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 drill of the present invention includes: a drill main body; a plurality of convex-arc cutting edges which are formed on a tip side of the drill main body from an outer periphery of the drill main body to a chisel edge provided near to a rotational axis; second faces which are each formed in an approximately band shape and are each formed along each of the convex-arc cutting edges on a back side of the convex-arc cutting edge in the rotational direction; third faces which are each formed to be continuous with a back side of each of the second faces in the rotational direction; and fourth faces which are each formed to be continuous with a back side of each of the third faces in the rotational direction.

Abstract: An insert detachably attached to an indexable rotary cutting tool, having 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 having 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 having 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 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 multi-flute ball end mill of the present invention includes: a shank portion configured to rotate about a rotational axis; a cutting edge portion; three or more ball edges formed on the cutting edge portion; gashes formed between the ball edges; peripheral cutting edges continuous with end portions of the ball edges on the shank portion side; and flutes formed between the peripheral cutting edges continuously with the gashes. The degree of curvature of the ball edges is 35% to 55%. Each of the gashes includes four faces of a rake face of each of the ball edges, a gash wall face, a first gash face, and a second gash face. The second gash face is formed such that the closer the second gash face is to the rotation center point, the more inwardly the second gash face enters a second face of each of the ball edges.

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: In the cutting insert of the present invention, the cutting edge portion includes: a first corner edge; a major cutting edge continuous with a first end portion (S1) of the first corner edge near the short-side-direction side surface and formed into a straight line; a first minor cutting edge continuous with a second end portion (S2) of the major cutting edge and formed into a circular arc; and a second minor cutting edge continuous with a third end portion (S3) of the first minor cutting edge and formed into a straight line. In a cross-sectional view of a rake face of the second minor cutting edge perpendicular to the second minor cutting edge, a cross-sectional ridgeline of the rake face of the second minor cutting edge is formed into a convex shape protruding above a cross-sectional ridgeline of a reference plane.

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: 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: A cutting tool cover set to a cutting tool which includes a hollow shaft body and at least one insert attached to an end face of the shaft body and cuts by bringing the insert into contact with a work while rotating the shaft body. The cutting tool cover includes: a body portion fixed to a top end portion of the shaft body; and an extension portion extended outward from the circumferential edge of the body portion in the entire circumference of the top end portion of the body portion to cover the surface of the work.

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: A drill of the present invention includes: a drill main body; a plurality of convex-arc cutting edges which are formed on a tip side of the drill main body from an outer periphery of the drill main body to a chisel edge provided near to a rotational axis; second faces which are each formed in an approximately band shape and are each formed along each of the convex-arc cutting edges on a back side of the convex-arc cutting edge in the rotational direction; third faces which are each formed to be continuous with a back side of each of the second faces in the rotational direction; and fourth faces which are each formed to be continuous with a back side of each of the third faces in the rotational direction.

Abstract: Square end mill includes long end cutting edge disposed from end portion on outer peripheral side in radial direction to center in the radial direction when a cutting edge portion is viewed from end face side, and short end cutting edges disposed from other end portions on outer peripheral side in radial direction to middles on center side in radial direction, first gashes disposed on regions from lines connecting end portions on center side in radial direction of the short end cutting edges to center in radial direction to the long end cutting edge on rear side in the rotation direction, second and third gashes disposed on rear and front sides in rotation direction of the first gashes, and all gashes formed in curved surface shapes depressed to a shank side on opposite side in axial direction of the cutting edge portion.