Forstner drill bit

Abstract

A modified Forstner type drill bit includes a shank and a drill head. The drill head includes a center brad, first and second radial cutters, first and second following rims and first and second chip channels. The center brad defines a longitudinal direction. The first and second of radial cutters extend radially from the center brad. The first and second following rims extend circumferentially from and following from in the direction of rotation the distal end of the first and second radial cutters respectively. Each following rim is divided into a plurality of segments, each have a top portion. The top portion of the segments of each following rim are generally in the same plane. The first and second chip channels are positioned adjacent to and before in the direction of rotation the first and second radial cutters respectively. The first and second chip channels are between the one of the first and second radial cutter and the second and first following rims. The shaft extend longitudinally from the radial cutters in the longitudinal direction and from the side opposed from the center brad. In one embodiment a plurality of depressions divide each following rim into segments. In another embodiment a plurality of elongate grooves divide each following rim into segments.