7-Piece Multi-Purpose Drill-Bit-Set

Up to 3 to 4 times stronger than the typical single purpose bit. Cuts through hardened steel, ceramic tile, marble, plastic, cast-iron, concrete, porcelain, glass, and woods. Negative back grinding enables tip to bore through materials with a filling action. Designed for rotary or percussion drilling. Cobalt and tungsten carbide drill bit tip designed for maximum hardness and resistance to heat (up to 1900 F.) and wear. Chrome vanadium steel shank. Carded.No. 01505: 5-piece (1/8", 3/16", 1/4", 5/16", 3/8")No. 01510: 7-piece set (1/8", 3/16", 1/4", 5/16", 3/8", 7/16", 1/2")