A cutting insert in a non-limiting aspect of the present disclosure may include an upper surface having a polygonal shape and including a first side, a lower surface, and a lateral surface. The lateral surface may include a first lateral surface located between the first side and the lower surface. The first lateral surface may include a first region that is flat. The first region may include a first central region, a first upper region and a first lower region. The first upper region may be located closer to the upper surface than the first central region, and may have a larger width than the first central region. The first lower region may be located closer to the lower surface than the first central region, and may be a larger width than the first central region.

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.

A mold machining method using an endmill, the contour of a cross section of the mold being concave and continuous in an area, a ratio of the maximum to the minimum of radius of curvature of the contour of a portion of the area (a first area) being 2 or greater, and a blade of the endmill having a second area where the contour of a cross section is similar to the contour of the first area, the method comprising the steps of determining a spiral path of the endmill such that each point of the first area is machined by a portion of the second area, corresponding to said each point in the similarity, and a radial interval between the spiral tool path is maximized while keeping surface roughness of the machined mold at or below a predetermined value; and machining the mold along the path.

A chamfer tool which comprises a tool holder. The tool holder extends along a central axis and comprises a plurality of slot-shaped cutting insert receptacles, each having two opposing lateral abutment surfaces and a base abutment surface arranged between the two lateral abutment surfaces and extending transversely thereto. The chamfer tool further comprises a plurality of cutting inserts, which are fixed in the plurality of cutting insert receptacles in a firmly bonded manner, wherein each of the cutting inserts comprises two opposing lateral surfaces, which abut against or are connected in a firmly bonded manner to the two lateral abutment surfaces of the respective cutting insert receptacle, and a lower surface arranged between the two lateral surfaces and extending transversely thereto, wherein the lower surface abuts against or is connected in a firmly bonded manner to the base abutment surface of the respective cutting insert receptacle. The cutting inserts project out of the first cutting insert receptacles both in an axial direction, which is parallel to the central axis of the tool holder, and transversely to the axial direction. Each of the cutting inserts comprises a main cutting edge which is oriented at a first acute angle to the central axis of the tool holder.

An indexable milling cutter includes a milling cutter body with a plurality of flutes and a plurality of seating surfaces adapted to mount a cutting insert thereon. The milling cutter body includes a plurality of coolant reservoirs in fluid communication with an adapter. In one aspect, each coolant reservoir lies along a circular intersection line of a coolant manifold. In another aspect, a longitudinal axis of each coolant reservoir is oriented at a non-zero angle, A, with respect to a central, longitudinal axis of the milling cutter. A plurality of coolant ducts in fluid communication with each coolant reservoir, each coolant duct having a smaller cross-sectional area than the coolant reservoir, provide multiple streams of coolant targeted at a plurality of specific critical cutting areas of the cutting insert.

A milling tool is configured from a shank part and a head with a cutting edge that is provided on the leading end of the shank part. The head comprises an expanding diameter section, the diameter of which expands gradually from the base end that contacts the shank part in the direction of the leading end, and a decreasing diameter section, the diameter of which gradually decreases from the maximum diameter section in the direction of the leading end. At least one cutting edge is provided on each of the expanding diameter section and the decreasing diameter section.

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°.

A milling tool having a front end, a rear end, a longitudinal axis extending therebetween, a shank portion and a cutting portion. The cutting portion includes a plurality of teeth separated by a corresponding number of flutes. Each tooth extends axially along the cutting portion following a curved helical path around the longitudinal axis, and extends at a first helix angle from the front end to a helix transition, and at a second helix angle from the helix transition towards the shank portion. The second helix angle is greater than the first helix angle by at least 2° and at most 15°. The first helix angle (α) is 33°≤α≤50°, and the second helix angle (β) is 40°≤β≤55°, and wherein the helix transition is axially located from the front end by 0.2 to 0.7 of the longitudinal length of the cutting portion.

A milling tool having a front end, a rear end, a longitudinal axis extending therebetween, a shank portion and a cutting portion. The cutting portion includes a plurality of teeth separated by a corresponding number of flutes. Each tooth extends axially along the cutting portion following a curved helical path around the longitudinal axis, and extends at a first helix angle from the front end to a helix transition, and at a second helix angle from the helix transition towards the shank portion. The second helix angle is greater than the first helix angle by at least 2° and at most 15°. The first helix angle (α) is 33°≤α≤50°, and the second helix angle (β) is 40°≤β≤55°, and wherein the helix transition is axially located from the front end by 0.2 to 0.7 of the longitudinal length of the cutting portion.

A beveling cutter (1) is provided in which a cutting blade (10) is composed of, when seen from an axial direction (X): an inner cutting blade portion (16) extending linearly toward a rear side R2 in a rotational direction R and toward the outer peripheral side; an outer cutting blade portion (17) extending linearly toward a forward side (R1) in the rotational direction (R) and toward the outer peripheral side on the radially outer side of the inner cutting blade portion (16); and a bending cutting blade portion (18) that connects the outer peripheral end of the inner cutting blade portion (16) with the inner peripheral end of the outer cutting blade portion (17). During a beveling operation, a cutting force vector (V1) applied from the inner cutting blade portion (16) to an edge portion (3) of a workpiece (2) and a cutting force vector (V2) applied from the outer cutting blade portion (17) to the edge portion (3) of the workpiece (2) are directed toward the center in the width direction of a bevel (5) formed by cutting. Formation of Poisson burr can thus be suppressed.