Abstract: A wire drawing die 1 includes a non-diamond material, is provided with a die hole 1h, and has a reduction 1c and a bearing 1d that is positioned downstream of the reduction 1c. A reduction angle ? which is an opening angle of the die hole 1h at the reduction 1c is less than or equal to 17°, and a surface roughness Ra of the die hole 1h within ±20 ?m from a specific position inside the bearing 1d in a circumferential direction of the die hole 1h that is perpendicular to a wire drawing direction is less than or equal to 0.025 ?m.

Abstract: An outer peripheral cutting edge located on a rear side in a rotation axis direction of the inclined cutting edge, a rotation diameter of the base metal on the rear side in the rotation axis direction of the outer peripheral cutting edge is smaller than a rotation diameter of the outer peripheral cutting edge, in a cross section perpendicular to a direction in which the inclined cutting edge extends, a cutting edge ridge of the inclined cutting edge has a roundness of a radius less than or equal to 30 ?m, and a maximum height difference value of the cutting edge ridge of the inclined cutting edge is less than or equal to 20 ?m.

Abstract: A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25?n/N?0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.

Abstract: A cBN sintered body has 40%-85% cBN by volume and 15% to 60% binder phase by volume. and inevitable impurities. The binder phase has an Al compound including Al and at least one element selected from N, O and B, and a Zr compound including Zr and at least one element selected from C, N, O and B. The Zr compound includes ZrO, or ZrO and ZrO2. In an X-ray diffraction, where a peak intensity of a (111) plane of the ZrO is I1, a peak intensity of a (101) plane of tetragonal ZrO2 is I2t and a peak intensity of a (111) plane of cubic ZrO2 is I2c, a ratio of the intensity of I1 to total intensities of I1, I2t and I2c is 0.6-1.0, and an average grain size of the Al compound is 80 nm-300 nm.

Abstract: A cBN sintered body has 40%-85% cBN by volume and 15% to 60% binder phase by volume. and inevitable impurities. The binder phase has an Al compound including Al and at least one element selected from N, O and B, and a Zr compound including Zr and at least one element selected from C, N, O and B. The Zr compound includes ZrO, or ZrO and ZrO2. In an X-ray diffraction, where a peak intensity of a (111) plane of the ZrO is I1, a peak intensity of a (101) plane of tetragonal ZrO2 is I2t and a peak intensity of a (111) plane of cubic ZrO2 is I2c, a ratio of the intensity of I1 to total intensities of I1, I2t and I2c is 0.6-1.0, and an average grain size of the Al compound is 80 nm-300 nm.

Abstract: A cubic boron nitride sintered body has between 50% and 75% cubic boron nitride by volume and between 25% and 50% binder phase by volume, and inevitable impurities. The binder phase contains an Al compound and a Zr compound. The Al compound contains Al and one or more of N, O and B; and the Zr compound contains Zr and one or more of C, N, O and B. At a polished surface of the cubic boron nitride sintered body, 40% or more of the Zr compounds satisfy the ratio 0.25?n/N?0.8, where: N represents the number of line segments drawn radially at equal intervals from a center of gravity of a given Zr compound to a boundary with a non-Zr compound; and n represents the number among those N line segments which intersect a boundary between the given Zr compound and cubic boron nitride.