Abstract: A rotary cutting tool having a plurality of removable cutting inserts is provided. The rotary cutting tool comprises a rotary tool body for rotation about a central shaft. A plurality of slots extend radially inwardly from the outer peripheral edge of the tool body for supplying a plurality of cutting inserts. Each of the cutting inserts has a geometrical configuration. The geometrical configuration is for engagement with an annular rib on an attachment ring. A pair of attachment rings entrap the tool body and cutting inserts therebetween. The ribs on the attachment rings contact only the insert by way of an interference fit with the geometrical configuration on the tool insert and the geometry of the groove in the tool body thereby locking the tool insert with respect to the tool body.