Abstract: A blade type rotary cutter for cutting tapered holes in metal workpieces. The cutter blade is elongated and generally flat, being tapered in the "width" direction for applying the taper to the hole, and being tapered in the "thickness" direction so that the cutting edge along the length of the blade will lead the cutting edges proximate the point and thereby minimize point drift. All cutting edges of the blade are provided with a substantial negative rake for chip control, and the chips are blown out of the hole by jet streams of cutting fluid directed along the longitudinal cutting edges of the blade.