Indexable cut-off saw

A circular cut-off saw for cutting metal comprising a circular tool body for mounting on an arbour, said tool body having flat axially opposed side faces and a narrow outer periphery, and a plurality of circumferentially equally spaced cutting inserts mounted at the outer periphery of the tool body, said cutting inserts being arranged in cooperating groups of three such that the total width of the saw cut is divided between the actions of the three cooperating cutting inserts, each group of three cooperating cutting inserts comprising a central insert mounted centrally on the outer periphery of the tool body and left and right side inserts, each side insert presenting a straight cutting edge mounted in pockets extending into said axially opposed side faces of the tool body, each said central insert comprising a cylindrical cutter disc having a pair of axially opposed flat circular side faces joined by an outer peripheral wall, and an arcuate cutting edge being provided between a said circular side face thereof and the outer peripheral wall, each said cylindrical cutter disc being mounted on the outer periphery of the tool body while resting on a said circular side face thereof with the central axis of the cutter disc being within about 1.degree.-15.degree. of coincidence with a corresponding radius of the tool body, said central cylindrical insert of each group being adapted to remove a central portion of a total saw cut and said left and right inserts with straight cutting edges being adapted to remove the balance of the total saw cut.