A drill bit having an interior canal for liquid nitrogen to pass longitudinally through the body of the drill bit. The canal has, on the side of a cutting edge of the drill bit, at least one liquid nitrogen ejection duct that opens near the cutting edge which is formed by an insert made with polycrystalline diamond fixed to the body of the drill bit. A device for drilling a metal-composite stack includes the drill bit, a liquid nitrogen production unit and a distribution network to distribute the liquid nitrogen. The device drills through a metal-composite stack in a single pass of the drill bit. The liquid nitrogen at cryogenic temperature is conveyed close to the cutting edge, at least while the cutting edge is in contact with the metallic material.

Disclosed herein is workpiece support including a body comprising a radially contractible portion including a plurality of wall sections each having an inner wall surface, the wall sections being separated from one another by slots, and a biocompatible liner comprising a plurality of liner sections fixed to the inner wall surfaces of the plurality of wall sections. An assembly containing the workpiece support, and methods of making and using the workpiece support, also are disclosed.

A rotary cutting tool comprises an elongate body disposed about a longitudinal axis, the elongate body including a helical flute and a polycrystalline-diamond cutting tip. The cutting tip comprises an inner portion having an inner point angle and an outer portion having an outer point angle different from the inner point angle.

cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.

There is a demand for a cutting insert capable of machining a workpiece under a wide range of cutting conditions. The cutting insert has a first portion, and a second portion protruding from a front end of the first portion. The second portion has an upper surface, a cutting edge, a rising surface, and a connecting surface having a recessed curved surface shape. The rising surface is located closer to the first portion than the upper surface, and is inclined upward with increasing distance from the upper surface. The connecting surface is located between the upper surface and the rising surface, and is connected to the upper surface and the rising surface. In a cross section having a bisecting line of a first corner, a virtual extended line of the upper surface and a virtual extended line of the rising surface intersect at an acute angle.

cBN sintered material, including cBN particles; a binder phase; and a first phase, wherein the content of the cBN particles in the cBN sintered material is 25% to 80% by volume, the binder phase contains either or both of one or more first compounds, and a solid solution derived from the first compound, the first phase contains cobalt, tungsten, and at least one first element selected from the group consisting of the elements contained in the binder phase, the total content of cobalt and tungsten in the cBN sintered material is 1.0% to 6.0% by mass, the binder phase consists of multiple binder phase particles containing 50% or more of first binder phase particles on a number basis, surfaces of the first binder phase particles include 50% by area or more of a first region which is in contact with the first phase.