Abstract: A cutting-tool insert having a cutting edge at the periphery of at least one of its side faces, and a plurality of serrations in the cutting edge. The side faces of the insert are formed with a plurality of recesses between its center and the cutting edge. The plurality of recesses are spaced from each other around the center of the side face, and are also spaced from the serrated cutting edge, to define a margin between the cutting edge and the recesses extending continuously along the length of the cutting edge following the serrations. Also described is a cutting tool using such inserts.