Abstract: A polygonal cutting insert is formed with a polygonal cutting face, an opposite support face generally congruent and generally parallel to the cutting face, and a plurality of generally planar side faces extending generally transversely between the cutting and support faces and meeting at corners. The side faces and corners define a cutting edge at a periphery of the cutting face and each side face is formed by at least two side-face regions extending parallel to each other and to the cutting and support faces and forming respective different side angles with the cutting face. Respective corner surfaces extending between the cutting and support faces at the corners each extend between a respective pair of side faces. Each such corner surface has a predetermined width that is greatest at the support face.

Abstract: The invention relates to a cutting insert (100; 200) for material-removing machining, especially turning, grinding, engraving and boring a workpiece (36), the at least one-sided overlap of which forms the first face (28) with at least one cutting edge (26) and the surrounding side surfaces of which form at least one free face (29). To improve cutting effectiveness, the flank (29) has one or more recesses (32) at a distance (h.sub.1) from the cutting edge (26; 34).