Diamond Drill Bit with Center Drill, 16-110mm Hole Saw Core Drill Bit Cutting Tools for Glass/Ceramic/Porcelain/Marble/Tile Diamond Coated Drill Bit A high-quality diamond coating improves drilling speed, making the bit sharper. Opening the hole with a center drill makes drilling easier. Slotted Flute Design The slotted edges make it sharper, making work more efficient. The side holes help to easily remove waste while dissipating heat when cutting the material. Stable and Durable Excellent tool for any DIY enthusiast working in the kitchen, bathroom, shower, ceramic, porcelain, glass, and marble. Nickel-plated surface for extended life and increased resistance to surface corrosion. The universal round handle is suitable for electric drills and impact drivers. Specifications Material: High quality steel, diamond coating. Color: Silver. Diameters: 16mm, 18mm, 20mm, 22mm, 25mm, 28mm, 30mm, 32mm, 35mm, 38mm, 40mm, 42mm, 45mm, 50mm, 53mm, 55mm, 60mm, 65mm, 68mm, 70mm, 75mm, 80mm, 85mm,