The invention relates to a cutting insert (10) with 8 usable cutting edges and with large longitudinal surfaces, each comprising a protruding rib (20) in the center along their longitudinal axes. The cutting edges (13) defining said longitudinal surfaces form an angle of 70°<(90°-beta)<90° with their respective ends and the short rounded edges (14) of the upper and lower surfaces (11, 12). According to the invention, milling tools are fitted with a plurality of such cutting inserts.
