Make your fasteners look clean and flush with a countersink. Countersinks are tools used for cutting angled holes in a work piece. They have fluted designs and are used to make clean cuts in hardwood, metal, plywood, and plastic. Cobalt countersinks are somewhat harder than high-speed steel and are often used for cutting stainless steel and other alloys. The fluted countersink cutter is used to provide a heavy chamfer in the entrance to a drilled hole. This may be required to allow the correct seating for a countersunk head screw or to provide the lead in for tapping. Our cobalt countersinks come in 1/4", 3/8", 1/2", 5/8" and 3/4" sizes. Larger sizes available by special order, up to 1 1/2" with 3/4" shank.