General Tools 6" Max Circle Cutter - Adjust from 1" to 6" diameter circles. Square shank. Replaceable 3/16" high-speed steel bit and 1/4" pilot drill. Made of heat-treated tool steel. For use in drill press, drill stand, or bit brace. Hex wrench included. - Circle Size: 1" To 6" Dia, Shank Diameter: 1/4" Square, Pilot Drill: 1/4", Bit Size: 3/16"