A cutting insert has a top surface and a bottom surface having a parallelogram shape, and four side surfaces connecting the top and bottom surfaces. One or more primary cutting edges are formed at intersections between the top and bottom surfaces and two opposing side surfaces. Secondary cutting edges are formed at intersections between the top and bottom surfaces and two other opposing side surfaces. The primary cutting edge forms a first angle with respect to a median plane parallel to the top and bottom surfaces. The secondary cutting edge forms a second angle with respect to the median plane. The top and bottom surfaces have a mounting surface and a rack surface, wherein the rack surface extends inwardly from the cutting edge toward the median plane. The top and bottom surfaces of the cutting insert have mirror symmetry with respect to the median plane.