ARTU 5-Piece Multi-Purpose Drill Bit Set Designed for rotary or percussion drilling. Negative back grinding enables tip to bore through materials with a filing action. Cobalt and tungsten carbide drill bit tip designed for maximum hardness, wear and resistance to heat up to 2000 F Degree Fahrenheit Resharpenable. Chrome vanadium steel shank for strength and flexibility. Bit has a flat bottom parabolic flute for faster waste removal. Drills through hardened steel, ceramic tile, marble, plastic, cast metal, concrete, glass, plexiglass, granite, fiberglass, brick, masonry, PVC polyvinyl chloride , and wood. Conforms to ANSI American National Standards Institute standards. Set includes 1 each 1/8 , 3/16 , 1/4 , 5/16 , 3/8 . Pieces In Set 5 pcs, Pkg Qty 5, Package Type Card