Abstract: A disk cutter including an annular disk-shaped base adapted to be driven about an axis of rotation, a plurality of tip supports formed along the outer circumference of the base integrally therewith so that a gullet is defined between adjacent ones of the tip supports, and a plurality of sets of tip inserts respectively fixed to the tip supports. Each set of tip inserts includes a pair of inclined tip inserts having oppositely inclined flanks with the same transverse clearance angle and oppositely inclined rakes with the same transverse rake angle. Each inclined tip insert has an inclined cutting edge such that a leading corner in respect of rotation of the base is lower in level than a trailing corner. The amount of sideward projection of the leading corner from the surface of the corresponding tip support is set larger by a given amount than that of the trailing corner.