Diamond Drill Bit with Center Drill, 16-110mm Hole Saw Core Drill Bit Cutting Tools for Glass/Ceramic/Porcelain/Marble/Tile Diamond Coated Core Bit High quality diamond coating improves drilling speed, making the drill bit sharper. Hole opening with center drill makes drilling easier. Chip Flute Design Slotted edges make it sharper, work more efficient. Side holes help to easily remove waste while dissipating heat when cutting material. Stable and Durable Great tool for any DIY enthusiast working in kitchen, bathroom, shower, ceramic, porcelain, glass and marble. Nickel plating on the surface for extended life and increased resistance to surface corrosion. Universal round handle fits for electric drills and impact drills. 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,90mm,95mm,100mm,105mm,110mm. Package Included: The purchased quantity shall prevail. Note Please make sure that water should be added during drilling to prevent it from being burned. Reduce the drilling speed, its internal pressure and improve the use of water lubrication to greatly protect the drill bits.