Abstract: An on-edge, double positive rake, indexable cutting insert in which a short cutting edge is formed along one side of one face surface of the insert while a longer cutting edge is formed along an angularly related side of the other face surface of the insert. Inserts of this type are particularly well suited for use as the outer inserts in an end mill having helical slots for receiving the inserts. When so used, two inserts are placed in side-by-side relation in one slot with their short cutting edges located in active cutting position while one insert is positioned in an adjacent slot with its long cutting edge located in active cutting position and axially overlapping the gap between the two short cutting edges. With this arrangement, material which is left uncut between adjacent inserts in one slot is cut away by the overlapping insert in the adjacent slot. Each insert includes edge surfaces defining clearance faces for the two cutting edges and enabling each cutting edge to make a right angle cut.