Made of chrome vanadium steel shank for enormous strength, for use with Tapcon fasteners. Special negative back grinding enables the tip to bore through applications such as masonry, ceramic tile, concrete, brick, fiberglass, plexiglas, cast metals, hardened steel, granite, marble, woods and plastic with a filing action rather than a cutting action. Requires no center punch, eliminates walking and can be re-sharpened. NOTE: not recommended for use on mild steel, e.g. aluminum, angle iron, copper, galvanized pipe, brass and stainless steel. Conforms to ANSI standards.Chrome vanadium steel shank for enormous strength and flexibilityOutlasts regular carbide-tipped bitsRequires no center punch and eliminates walkingResharpens on a high-quality silicon carbide grinding wheelUses standard coolants such as turpentine, light oil, waterFlat bottom parabolic flute for faster waste removalSpecial negative back grinding enables the tip to bore through materials with a filing action, not cuttingThe blend and high tech bonding of cobalt and tungsten carbide allows bit to withstand temperatures up to 2000 deg F