Trend Snappy SNAP/GD/8MM Glass Drill 8mm The Trend Snappy SNAP/GD/8MMTCT drill bit is designed to be used in conjunction with quick chucks and power drills for use on glass, porcelain, tile and mirrors. Its TCT construction ensures maximum strength and long life. Features: For use on glass, porcelain, tile and mirrors Not for use on toughened glass A coolant must be used TCT for extra long life and durability Specification: D:8 mm Shank Diameter: 1/4 inch hex