Abstract: A transmission X-ray diffraction on a cross section of a boron nitride sintered body perpendicular to a first surface provides X-ray intensities at a top of a 111 diffraction peak of cubic boron nitride and X-ray intensities at a top of a 002 diffraction peak of compressed boron nitride, in a direction perpendicular to the first surface and a direction parallel to the first surface. A compressed boron nitride content value obtained from these X-ray intensities is greater than 0.002 and smaller than 0.01. A cubic orientation value is greater than 0.5, and a compressed boron nitride orientation value is greater than the cubic orientation value. An insert has a coating layer on at least a part of a surface of the boron nitride sintered body.

Abstract: An insert of the present disclosure includes a boron nitride sintered body including a first surface. In a transmission X-ray diffraction of a cross section of the boron nitride sintered body vertical to the first surface, X-ray intensity at a top of a 111 diffraction peak of cubic boron nitride in a direction vertical to the first surface is IcBN(111)v. X-ray intensity at a top of a 002 diffraction peak of compressed boron nitride is IhBN(002)v. X-ray intensity at a top of a 111 diffraction peak of the cubic boron nitride in a direction parallel to the first surface is IcBN(111)h. X-ray intensity at a top of a 002 diffraction peak of the compressed boron nitride is IhBN(002)h. A compressed boron nitride content value obtained from these X-ray intensities is larger than 0.005. A cubic orientation value is larger than 0.5, and a compressed boron nitride orientation value is larger than the cubic orientation value.