The product is also called tricorn bit which is used for the drilling of ceramic tile, ceramic, glass, granite and cement. Notice: The product cannot work on armoured glass and not suitable for complete ceramic tile, porcelain tile and marble. The carbide cutter head, milled through diamond grinding wheel, is used in the centering drill. The cutter head made of brazing alloy with rectangular shank could be installed in such devices as regular electric hand drill, electric drill, bench drill and flat drill with clamping chuck no less than 10mm.