For rotary or percussion drilling. Chrome vanadium steel shank with cobalt and tungsten carbide tip that withstands temperatures up to 1900 deg F. Special negative back grinding enables tip to bore through applications such as masonry, ceramic tile, concrete, brick, fiberglass, plexiglass, cast metals, hardened steel, granite, marble, woods and plastic with a filing action rather than a cutting action. No center punch required, eliminates walking and can be re-sharpened. This includes aluminum, angle iron, copper, galvanized pipe, brass and stainless steel.