A rotary cutter for a brush cutter. The cutter has a rotatable cylindrical drum with a plurality of flat, annular, collars mounted on the drum. The collars are fastened to the drum by their inner circular edge, are equally spaced apart on the drum, and extend transverse to the rotational axis of the drum. A cutting tooth mounting block is mounted between each adjacent pair of collars, the block located at the outer edge of the collars and spaced above the surface of the drum to provide a gap for passing chips and residue. The mounting block carries a detachable cutting tooth, the tooth extending forwardly generally tangentially from the block and terminating in a cutting edge above the collars.
