Diamond Drill Bits, LepoHome 10 PCS Hollow Core Bit Set for Ceramic, Glass, Porcelain Tile Hole Saw Glass Bit, 1/4 to 1 1/5 Inch

10 Sizes(Diameter): 6mm(1/4"), 8mm(5/16"), 10mm(3/8"), 12mm(1/2"), 14mm(0.55"), 16mm(5/8"), 18mm(11/16"), 20mm(3/4"), 22mm(7/8"), 30mm(1-1/5"). Satisfy most of your different needs. Rustless & Sturdy: Made of high strength Carbon Steel with smooth nickel plating surface to extend the service life. Quick, Sharp & Smooth Cut: Coated with high quality Diamond to enhance the drilling speed and creates a sharp, high precision and smooth cut with no broken edges In Seconds. Application: Drill Glass, Tile Bottles, Blocks Jars, Fiberglass Porcelain Tile Ceramic, Slate Mable, Granite Light Stone.Not for use on Concrete or for depths beyond about 1/2". Attention: Please keep the speed in 800-1000 per minute, keep adding water to keep the drill cool, strictly prohibit from dry drilling.