Abstract: A cutting insert has two cutting heads that are opposite with respect to the longitudinal axis A of the insert. Each of the cutting heads has a cutting edge running substantially transversely to the longitudinal axis A and two side cutting edges or cutting-edge sections running substantially in the direction of the longitudinal axis A of the cutting insert. The side cutting edges run so as to fall away from the end cutting edge with respect to the tool reference plane Pr. The flanks, lying on the same side of the cutting insert, of the side cutting edges of the opposite cutting heads in each case lie on a common plane E. This makes possible more cost-effective grinding of the side cutting edges.