Hole Saw - SODIAL(R) 12mm Diamond Tipped Metal Hole Saw Drill Bit for Ceramic Tile Glass Diamond coated tip and sturdy metal body, gives good performance and longer life. Designed for drilling 1/2inch diameter holes. Used on glass, ceramic, porcelain, tile, limestone, slate, marble, granite, stone, and fiberglass. Works better with an electric drill which is not included here.?