Milwaukee 48-20-8992 1/4” Natural Stone Bit Our Milwaukee 48-20-8992 1/4” Natural Stone Bits deliver up to 2x life in granite, stone, ceramic tile, and glass. Hammer mode capability provides faster drilling speeds when drilling natural stone tiles, like granite and marble. Equipped with an aggressive 8-grind carbide head, these bits deliver up to 20% faster drilling. These Milwaukee 48-20-8992 1/4” Natural Stone Bitts feature reinforced tips that protect the carbide head, providing the durability needed for use in hammer drill mode. Milwaukee 48-20-8992 1/4” Natural Stone Bits can be used in drill-only mode or hammer drill-mode, and we don’t recommend them for porcelain tile.