Abstract: A rotary cutter is disclosed herein having a hollow body adapted to be mounted on to the chuck of a power driven device such as a hand drill or the like. Within the hollow of the body, there is a metallic and magnetic member formed with a central slot or groove. A circular cutter is insertably received within the hollow of the body and includes projections which make and engage with the slot of the magnetic. The circular cutter is maintained in position on the body by the force of magnetic attraction and the rotating power of the body is imparted to the circular cutter by engagement of the projection in the slotted magnet. A circular cutter includes a tapered cutting edge which is disposed outwardly from the body so that only the circular cutting edge will engage with a work piece.