A cutting insert may include an upper surface, a lateral surface, and a cutting edge including a boundary between the upper surface and the lateral surface. The upper surface may include a first rising face that extends upward and a second rising face that is connected to an upper side of the first rising face and extends upward. The first rising face may include a first region that extends along a corner portion and a second region that extends along a side portion. The second rising face may include a third region connected to the first region and a fourth region connected to the second region. An entirety of a boundary between the first region and the third region may be positioned above the cutting edge. A boundary between the second region and the fourth region may include a portion disposed below the cutting edge.

This disclosure relates to a high cBN content polycrystalline cubic boron nitride, PCBN, material. The binder matrix material comprises 2 to 15 wt. % titanium diboride (TiB2).

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.

A turning insert includes a head portion connected to a stem portion. A CBN cutting edge includes a surface generating cutting edge and two major cutting edge portions, such that each major cutting edge portion forms an angle of 5-20° in relation to a tangent line of the cutting edge at a forward point of the cutting edge.

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/cm.sup.3 and no more than 3.5 g/cm.sup.3, 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.

A cBN sinter comprising cubic boron nitride grains and a binder phase, the binder phase comprising Ti.sub.2CN and Co.sub.2B, wherein the ratio I.sub.Ti2CN/I.sub.Co2B of a peak intensity I.sub.Ti2CN assigned to Ti.sub.2CN appearing at 2θ = 41.9° to 42.2° to a peak intensity I.sub.TiAl3 assigned to Co.sub.2B appearing at 2θ = 45.7° to 45.9° is in a range of 0.5 and 2.0 in an XRD measurement.

The disclosure relates to a method of manufacturing a cutting tool including the steps of: providing a cutting tool blank including a cutting edge, defined by a cross-sectional wedge angle (β). The wedge angle has a variation along the cutting edge, and material is removed from the cutting edge with a constant material removal rate per length unit of the edge, such as to form a corresponding variation of edge rounding along the cutting edge. The disclosure further relates to a cutting tool including the cutting edge defined by the cross-sectional wedge angle having a variation along the cutting edge and wherein the cutting edge has a corresponding variation of edge rounding along the cutting edge.

A cubic boron nitride-based sintered material includes cubic boron nitride particles of 70 to 95 vol %, in which in a structure of a cross-section of the sintered material, a binder phase with a width of 1 nm to 30 nm is present between the adjacent cubic boron nitride particles, the binder phase being made of a compound containing at least Al, B, and N and having a ratio of an oxygen content to an Al content of 0.1 or less in terms of atomic ratio.

There are provided a cubic boron nitride sintered body having a surface also excellent in adhesiveness to a ceramic coating film, while having excellent wear resistance and defect resistance, and a manufacturing method thereof, and a tool. The cubic boron nitride sintered body of the present invention includes 60.0 to 90.0% by volume of cubic boron nitride, the remainder being a binder phase, wherein the binder phase contains: at least any of a nitride, a boride, and an oxide of Al; at least any of a carbide, a nitride, a carbonitride, and a boride of Ti; and a compound represented by the following formula (1):

W.sub.2Ni.sub.xCo.sub.(1-x)B.sub.2(0.40≤x<1)  (1)

A surface-coated cutting tool has a hard coating layer on a tool body. The hard coating layer includes a (Ti.sub.1−xAl.sub.x)(C.sub.yN.sub.1−y) layer (the average amount Xavg of Al and the average amount Yavg of C satisfy 0.60≦Xavg≦0.95 and 0≦Yavg≦0.005). Crystal grains having an NaCl type face-centered cubic structure in the layer have {111} orientation, a columnar structure in which the average grain width of the individual crystal grains having an NaCl type face-centered cubic structure is 0.1 μm to 2.0 μm and the average aspect ratio is 2 to 10 is included, and in the individual crystal grains having an NaCl type face-centered cubic structure, a periodic compositional variation in Ti and Al in the composition formula: (Ti.sub.1−xAl.sub.x)(C.sub.yN.sub.1−y) is present and the difference between the average of maximum values of x and the average of minimum values thereof is 0.03 to 0.25.