General description Diamond Glass Hole Saw Drill Bit with Center Pilot Tip is designed for precise drilling in glass, ceramic tiles, stone, and granite. The pilot bit in the center ensures accurate hole cutting, making the drilling process easier and more efficient. Technical specifications Diameter: 40mm Material: Diamond-coated Maximum drilling depth: 1/2 inch Usage Water lubrication is required during drilling to enhance performance and prolong the life of the drill bit. Not suitable for use on concrete. Other information White zinc plating on the bits provides high corrosion resistance, maximizing tool life. Clearance hole design allows for cooling water entry and chip evacuation.