A slotting cutter includes a circular disc having an outer periphery along which a plurality of chip channels are formed which define respective seats for receiving respective index able cutting inserts. Each insert includes a planar bottom side. Either the seat or the bottom side has a male locator portion, and the other of the seat and the bottom side has a female locator portion which receives the male locator portion to define therewith and insert-locating structure. The male and female locator portions are offset laterally from a center plane of the insert oriented perpendicular to an axis of rotation of the disc. Alternating ones of the insert-locating structures are disposed on respective opposite sides of the center plane.