Abstract: A rotary cutter head includes a rotary body, resilient clamping arm, and at least one cutting blade. The clamping arm clamps the cutting blade radially inwardly first rather than in a circumferential direction in order to positively lock the cutting blade radially, and thereby prevent the cutting blade from migrating out of position slightly during high speed rotation of the cutter head.

Abstract: An indexable cutting insert, a tool using a plurality of such inserts, and a method of forming flat bottomed grooves in the backs of flooring planks. The tool is arranged to accept indexable inserts, and the indexable inserts are specially arranged such that each insert has four sets of cutting faces for forming a flat bottom groove with 45 degrees groove side walls. The insert is provided with a conical dished face on its unsupported side, and a mating conical faced nut is positioned in the dished face and receives a threaded fastener, preferably a cap screw, which projects through the tool body, through the insert aperture and into the nut to accurately lock the insert in indexed position in such a way that the head of the cap screw is substantially free of impacted cutting debris.