This single-flute Countersink has been one of our steadiest sellers over the years and we have continually improved it - providing it with a better cutting edge, making it chatterfree and spiffing up its general appearance. We now believe it to be the best general purpose woodworking countersink on the market, and perhaps deserving of some extra copy extolling its virtues. The Countersink is a natural companion to the Wood Threader - essential for making a neat bevel on a hole drilled for tapping, but it is also a great basic tool for smoothing rough edges, cutting an 82° chamfer on holes from 0 - 1" or countersinking screw heads of any size. We have it manufactured with a 3/8" shank so that you can use it on either a hand drill or a small drill press. It is an unpretentious - even humble - tool, but, like the right size screw driver, one very difficult to be without.