Shank Type: Round Shank (Size: 6mm, 8mm, 10mm) ; Triangle Shank (Size: 12mm – 100mm). After drilling the positioning slot, slowly straighten the drill and press down the hole at a constant speed. Suitable Materials: Ceramic tile, Vitrified tile, Ceramic, Glass, Marble, Granite, Microcrystalline stone, Quartz stone, etc.