A bore cutting tool for cutting metal workpieces includes a tool substrate and a tool coating on a surface of the tool substrate. The bore cutting tool includes a plurality of pits in the surface of the tool substrate and wherein the tool coating extends over the pits such that the pit surface includes the tool coating. In this way, the pit dimensions can be retained over prolonged tool life and the pits, with their coated surface, are particularly effective at retaining lubricant so that the thickness of a lubricant film can be increased as compared to a tool without the coated pits. In the embodiments, the pits are formed by laser etching and are present only on the cylindrical land. Average pit depth is suitably in the range 8 μm to 25 μm, average pit width and pit length is independently selected from 40 μm to 250 μm and average pit density may be 20 to 30 pits/mm.sup.2.

A tip (20) for a rotary machine tool comprising a superhard structure (12) joined to a cemented carbide substrate 14 by means of at least one intermediate layer (161, 62, 163) disposed between the superhard structure (12) and the cemented carbide substrate (14), the intermediate layer or layers (161, 162, 163) comprising grains of superhard material and grains of a metal carbide material dispersed in a metal binder material.

A reamer has a shank made of steel and a cutting body made of a harder material, wherein the cutting body forms the outer circumference of the reamer in the region of the workpiece side end and has all the cutting ribs.

The rotating tool, in particular a drill, includes a fluted cutting shank made of a resistant material, in particular carbide, extending in an axial direction along a rotational axis. Connecting to the cutting shank in the axial direction is an intermediate shank made of a material of greater elasticity in comparison the resistant material, in particular of tool steel. The intermediate shank includes an insertable cutting insert that may be exchanged. The cutting shank is preferably a cutting shank recycled from a used solid carbide drill.

A tool head for use with a modular shank tool includes at least two preforms. Each preform of the at least two preforms is made separately from the other preform of the at least two preforms from granular materials and then put together and jointly compressed and integrally bonded.

A reamer has a shank made of steel and a cutting body made of a harder material, wherein the cutting body forms the outer circumference of the reamer in the region of the workpiece side end and has all the cutting ribs.

A process for producing a tool having a main body which extends in a longitudinal direction and at least one blade for machining a workpiece includes providing a base coating on the tool; grinding the at least one blade in a manner that removes the base coating in the region of the at least one blade; and providing a second, fine coating, to the at least one ground blade.

A bore cutting tool for cutting metal workpieces includes a tool substrate and a tool coating on a surface of the tool substrate. The bore cutting tool includes a plurality of pits in the surface of the tool substrate and wherein the tool coating extends over the pits such that the pit surface includes the tool coating. In this way, the pit dimensions can be retained over prolonged tool life and the pits, with their coated surface, are particularly effective at retaining lubricant so that the thickness of a lubricant film can be increased as compared to a tool without the coated pits. In the embodiments, the pits are formed by laser etching and are present only on the cylindrical land. Average pit depth is suitably in the range 8 m to 25 m, average pit width and pit length is independently selected from 40 m to 250 m and average pit density may be 20 to 30 pits/mm.sup.2.

A drilling tool for producing drill holes includes a tip and a shaft arranged opposite the tip in a direction of a longitudinal axis of the drilling tool. The drilling tool has at least one geometrically defined cutting edge in the tip area, and has an expanded diameter trailing the tip in a longitudinal direction from the tip. The drilling tool has a first area with a first diameter that precedes the expanded diameter, and a second area with a second diameter, larger than the first diameter, that trails the expanded diameter. The drilling tool is distinguished in that the expanded diameter and/or the second area is/are embodied such that chips are produced in the area of the expanded diameter and/or in the second area when a workpiece is machined, chips consistent with those produced when a workpiece is machined with a geometrically undefined cutting edge.

A cutting tool based on an embodiment of the present invention is provided with a cylindrical main body section which is made of a cobalt-containing cemented carbide alloy and is rotatable about the central axis thereof, a cutting edge which is provided at at least one of the tip and the periphery of the main body section, a chip discharge groove which extends from the cutting edge toward the rear end of the main body section, and a coating layer which is made of diamond and covers the cutting edge, wherein the cobalt content of the surface of the main body section at the part coated with the coating layer is less than the cobalt content of the surface of the main body section at parts other than the part coated with the coating layer.