An indexable milling cutting insert includes an opposed outside and inside, a periphery, and a plurality of homologous and alternately individually usable cutting edges, which are equidistantly spaced apart from a center axis, which extends between the outside and inside. The cutting insert includes a plurality of countersunk chip channels, which are delimited by bottoms and tangentially spaced-apart ridges, which individually include a cutting edge formed between a chip surface included in a first chip channel, and a clearance surface, which borders on a second chip channel.

A tool for a chip removing machining includes a basic body and a replaceable cutting insert, which is indexable by a cutting edge exchange mechanism. The cutting edge mechanism includes an ejector, which in a front part has an attachment for the cutting insert and interacts with a device for transforming a rectilinear, axial projection of the ejector into a simultaneous turning of the same. The cutting edge exchange mechanism includes a stop collar, which is fixedly anchored in relation to the basic body, and through which the ejector is movable back and forth and a carrier included in a rear part of the ejector. In addition, between the carrier and the stop collar, there is arranged a mechanical compression spring, which spaces the carrier from the stop collar. In addition, an autonomous cutting edge exchange mechanism is disclosed.

A method for milling a planar surface, during which a milling cutter, an axis of rotation of which is perpendicular to a surface to be machined, is moved in a direction parallel to the plane of the surface, to machine the surface in a single machining operation, over a predetermined layer of material, using a single milling head, and the milling cutter, in a same axial position relative to the surface to be machined, simultaneously carries out rough working, at least one intermediate finishing operation, and a finishing operation over a same layer of material.

Cutting insert with a cuboid body has a substantially square top face and bottom face, said top face and bottom face connected by four peripheral adjoining side surfaces. At least two cutting edges are formed at the transition of the top face to at least two side surfaces, that cutting edges defining a plane of the top face. To provide a cutting insert and a corresponding tool suited to produce valve seat surfaces with high precision but still having a rather simple construction and being precisely mountable with ease and less efforts of adjustment, the plane defined by the top face cutting edges of the cutting insert has maximum dimensions of 7 mm7 mm, where the bottom face has a supporting surface formed exactly parallel to the plane defined by the top face cutting edges by means of grinding within a tolerance of less than 5 angular minutes.

An indexable milling cutting insert includes an opposed outside and inside, a periphery, and a plurality of homologous and alternately individually usable cutting edges, which are equidistantly spaced apart from a centre axis, which extends between the outside and inside. The cutting insert includes a plurality of countersunk chip channels, which are delimited by bottoms and tangentially spaced-apart ridges, which individually include a cutting edge formed between a chip surface included in a first chip channel, and a clearance surface, which borders on a second chip channel.

A tool for a chip removing machining includes a basic body and a replaceable cutting insert, which is indexable by a cutting edge exchange mechanism. The cutting edge mechanism includes an ejector, which in a front part has an attachment for the cutting insert and interacts with a device for transforming a rectilinear, axial projection of the ejector into a simultaneous turning of the same. The cutting edge exchange mechanism includes a stop collar, which is fixedly anchored in relation to the basic body, and through which the ejector is movable back and forth and a carrier included in a rear part of the ejector. In addition, between the carrier and the stop collar, there is arranged a mechanical compression spring, which spaces the carrier from the stop collar. In addition, an autonomous cutting edge exchange mechanism is disclosed.