Abstract: A cutter insert assembly for a drill bit for boring into the earth, comprising a super-hard structure clampable to a support body by means of a clamp mechanism; the clamp mechanism comprising opposed or opposable compression members connected or connectable by a tension member capable of sustaining a clamping force between the compression members when the cutter insert assembly is in a clamped condition, in which condition the compression members exert opposing compressive forces on the super-hard structure and the support body, operable to clamp the super-hard structure to the support body, and in which condition the cutter insert assembly is self-supporting and capable of being mounted onto a drill bit body.

Abstract: A polycrystalline superhard material comprises a mass of diamond, graphite or cubic boron nitride particles or grains bonded together by ultrathin inter-granular bonding layers, the inter-granular bonding layers having an average thickness of greater than about 0.3 nm and less than about 100 nm. There is also disclosed a method for making such a polycrystalline superhard material.

Abstract: A method of producing a tool insert which comprises a central metal portion having edge regions of superabrasive material bonded thereto and presenting cutting edges or points for the tool insert is disclosed. A body (50) having major surfaces on each of opposite sides thereof, each having spaced strips (64) of superabrasive material, typically abrasive compact such as PCBN or PCD, for example, separated by a metal region or regions, such as cemented carbide, is provided. Each superabrasive strip of one major surface is arranged in register with a superabrasive strip of the opposite major surface. Alternatively, each superabrasive strip extends from one major surface to the opposite major surface. The body is severed from one major surface to the opposite major surface along at least two sets of planes intersecting at or in the respective superabrasive strips to produce the tool insert.

Abstract: A cutter insert assembly for a drill bit for boring into the earth, comprising a super-hard structure clampable to a support body by means of a clamp mechanism; the clamp mechanism comprising opposed or opposable compression members connected or connectable by a tension member capable of sustaining a clamping force between the compression members when the cutter insert assembly is in a clamped condition, in which condition the compression members exert opposing compressive forces on the super-hard structure and the support body, operable to clamp the super-hard structure to the support body, and in which condition the cutter insert assembly is self-supporting and capable of being mounted onto a drill bit body.

Abstract: A method of producing a tool insert is disclosed. A body (50) of a superabrasive material having major surfaces on each of opposite sides thereof is provided. It is typically an abrasive compact disc such as a PCBN or a PCD disc, for example. An array of spaced cores (58) filled with hard metal, such as cemented carbide, for example, extends from one major surface to the opposite major surface. The body is severed from one major surface to the opposite major surface along intersecting, transverse lines (68) around the respective hard metal cores to produce the tool insert. The body may include an interlayer (56) of hard metal intermediate the opposite major surfaces, preferably the same hard metal as the cores, such that the cores are integrally formed with the interlayer.

Abstract: A method of producing a tool insert which comprises a central metal portion having edge regions of superabrasive material bonded thereto and presenting cutting edges or points for the tool insert is disclosed. A body (50) having major surfaces on each of opposite sides thereof, each having spaced strips (64) of superabrasive material, typically abrasive compact such as PCBN or PCD, for example, separated by a metal region or regions, such as cemented carbide, is provided. Each superabrasive strip of one major surface is arranged in register with a superabrasive strip of the opposite major surface. Alternatively, each superabrasive strip extends from one major surface to the opposite major surface. The body is severed from one major surface to the opposite major surface along at least two sets of planes intersecting at or in the respective superabrasive strips to produce the tool insert.

Abstract: The invention provides a method of manufacturing an abrasive body which includes the steps of providing a mixture comprising a mass of nanosized ceramic particles and a mass of ultra-hard abrasive particles, typically diamond and cubic boron nitride, and sintering the mixture into a coherent body. The sintering conditions used are hot-pressing conditions.