A method of efficiently forming a finished part, the method includes providing a cutting tool having a first cutting edge extending from a first end of the cutting tool, a second cutting edge extending from a second end of the cutting tool, and a shaping edge disposed between the first cutting edge and the second cutting edge. The cutting tool is advanced into a rotating workpiece such that the first cutting edge removes a trailing end of the rotating workpiece, the shaping edge shapes a working portion of the rotating workpiece, and the second cutting edge removes the working portion of the rotating workpiece to form the finished part.

To make it possible for bores (16) that are in line with one another to be efficiently worked by means of a boring bar (2), the boring bar has a main body (10) with an axis of rotation (R) and a number of cutting elements (12, 12A) at intervals from one another in the axial direction (4) and also guiding elements (14) for guiding the main body (10) in a guiding bore (16A). The guiding elements (14) are kept at a distance from the axis of rotation (R) equivalent to a guide radius (r1). The main body (10) is divided into a functional region (19) and an eccentric region (10), wherein the cutting elements (12, 12A) and the guiding elements (14) are arranged such that they are distributed around the main body (10) over an angular range (a) of less than 180°. Furthermore, the circumferential side (22) of the main body (10) can be passed eccentrically through a respective bore (16, 16A) of which the unworked tube radius (r2) is less than the guide radius (r1).

A cutting tool for boring (40) that is attached to a machining apparatus and used for cutting a hole (13) on a large-diameter side of a stepped hole of a workpiece (10) is provided. The cutting tool for boring (40) is a set of two tools, and each cutting tool for boring (40a, 40b) in the set of two includes a shaft part (41), a cutting blade (42) laterally protruding from the respective shaft parts (41), and an abutment surface (43) formed at the tip of each shaft part (41) and used to cause the tips of the respective shaft parts (41) to butt against each other. Each cutting tool for boring (40a, 40b) performs cutting while the two cutting tools for boring (40a, 40b) rotate integrally around the center line of the shaft parts (41) in a coupled state in which the tips of the cutting tools for boring (40a, 40b) are butted together.

The present application relates to a cutting tool (2), in particular a boring bar (2) for machining holes (16) separated from each other in an axial direction (4) by a given spacing distance (a), comprising a main body (10) extending in an axial direction (4) with an axis of rotation (R) with at least one cutting element (12), as well as with a number of guide elements (14) for guiding the main body (10) within a guide hole (16A), wherein the guide elements (14) for the axis of rotation (R) are separated by a guide radius (r1), wherein viewed in a cross-section, the main body (10) is divided into a functional region (19) and an eccentric region (20), wherein the cutting elements (12) and the guide elements (14) are arranged distributed over the circumference of the main body (10) over an angular region () of less than 180.

A cutting tool for forming a finished part from a rotating workpiece includes a first cutting edge extending from a first end of the cutting tool, a second cutting edge extending from a second end of the cutting tool, and a shaping edge disposed between the first cutting edge and the second cutting edge. The first cutting edge is operable to remove a trailing end of the rotating workpiece and the second cutting edge is operable to remove a working portion of the rotating workpiece disposed between the trailing end and a leading end. The shaping edge is operable to shape the working portion of the rotating workpiece by advancing the cutting tool into the rotating workpiece until the first cutting edge removes the trailing end of the rotating workpiece and the second cutting edge removes the working portion of the rotating workpiece to form the finished part.

The present application relates to a cutting tool (2), in particular a boring bar (2) for machining holes (16) separated from each other in an axial direction (4) by a given spacing distance (a), comprising a main body (10) extending in an axial direction (4) with an axis of rotation (R) with at least one cutting element (12), as well as with a number of guide elements (14) for guiding the main body (10) within a guide hole (16A), wherein the guide elements (14) for the axis of rotation (R) are separated by a guide radius (r1), wherein viewed in a cross-section, the main body (10) is divided into a functional region (19) and an eccentric region (20), wherein the cutting elements (12) and the guide elements (14) are arranged distributed over the circumference of the main body (10) over an angular region () of less than 180.

A method for roughening an inner surface (8) of a cylindrical bore (9), in particular a running surface in a cylindrical bore or cylinder liner of an internal combustion engine. A rotating tool (1) is moved in a translatory manner in the axial direction of the cylindrical bore (9) and has a radial cutting head (7). A chip (12) is lifted off by at least one cutting edge of the radial cutting head (7) and is broken away via a further edge or face of the radial cutting head (7), in order to produce the roughened surface. The tool (1) is introduced into the cylindrical bore (9) or is passed through it, after which a positioning of the tool (1) in the radial direction takes place, and after which the removal of the material takes place via the rotating tool (1) when the tool is moved in its advancing direction (V) out of the cylindrical bore. A tool (1) is also claimed.