This disclosure relates to a metal-cutting machine tool with a base body, which is rotatable about an axis of rotation relative to a workpiece to be machined, at least one plate seat disposed outside the axis of rotation on the base body and a cutting insert, which is inserted into the plate seat and held therein by at least one fastening means and which is provided with a coating, at least in the area of its cutting edge. In order to compensate for positional tolerances, according to this disclosure the plate seat comprises a positioning surface oriented toward the axis of rotation, and the cutting insert has a reference surface lying against the positioning surface and facing away from the axis of rotation, for radially determining the position of its cutting edge, wherein the coating is also applied to the reference surface.

This disclosure relates to a metal-cutting machine tool with a base body, which is rotatable about an axis of rotation relative to a workpiece to be machined, at least one plate seat disposed outside the axis of rotation on the base body and a cutting insert, which is inserted into the plate seat and held therein by at least one fastening means and which is provided with a coating, at least in the area of its cutting edge. In order to compensate for positional tolerances, according to this disclosure the plate seat comprises a positioning surface oriented toward the axis of rotation, and the cutting insert has a reference surface lying against the positioning surface and facing away from the axis of rotation, for radially determining the position of its cutting edge, wherein the coating is also applied to the reference surface.

A reaming tool includes a tool holder body and at least one one-piece indexable reaming insert. The reaming insert includes more than one cutting edge. The tool holder body has an insert clamp for clamping the reaming insert relative to the tool holder body. The cutting edge extends beyond a periphery of the tool holder body when the reaming insert is clamped relative to an abutment surface of the tool holder body. The reaming insert has a head and an integral mounting portion, the tool holder body having an opening in which the integral mounting portion of the cutting insert is disposed. A reaming insert for a tool is also disclosed.

A reamer has a basic tool body made of hard metal (12) and a plate-like cutting insert (18) inserted into a recess (28) at the front. The cutting insert (18) is at least partially made of polycrystalline diamond, its cutting edges (20) situated axially offset relative to the cutting edges (30) on the basic tool body (12), thus engaging with the workpiece later.