Artu-Usa 01150 Multi-Purpose Drill Bit, 1/4" x 16"Highlights: For rotary and percussion drilling Chrome vanadium steel shank with cobalt and tungsten carbide tip for increased strength and extra hardness Special negative back grinding enables tip to bore through steel, wood, tile, marble, porcelain, glass, concrete Plastic and cast iron with a filing action rather than a cutting action No center punch required, eliminates walking Withstands temperatures up to 1900 degrees Fahrenheit Easy to