For use with Hougen Portable Magnetic Drills and machine tools operations on materials up to 350 BHN. Made of hardened, high speed tool steel and precision ground, cutters feature a 3/4" diameter shank (Model HMD933 requires adapter #02386) and are available in 1, 2, 3, 4 & 6" D.O.C. Plus, modified end tooth geometry for stacked plate drilling is available. "12,000-Series" Annular Cutters are resharpenable using the 10950 Sharpening Machine.