s The diamond hole saw is made of high carbon steel with clean and smooth opening, no broken edges. Small incision resistance, stable drilling and won't break the border. Good Design Center pilot holes and side holes help to easily dispose of waste; Diamond drill bit has golden coating to prevent rusting, improve surface corrosion resistance. Wide Application Diamond drill bits can be used to drill ceramic tile, marble, glass, granite, concrete and other hard materials. Will work with all electric drills and hammer drills. It is suitable for DIY projects and home maintenance and repair. Please Note When cutting hard materials, it is important to ensure that the bit stays cool to prevent damage to the material being drilled and premature wear of the bit. Water is needed for lubrication when drilling, which can extend the life of the bit. We offer a TWO YEAR warranty on the hole saw. If you have any questions, do not hesitate to . We will try our best to solve it for you. (Please clamp the shaft in the right place and take the necessary protective measures during use.) Diamond Hole Saw Drill Bit Primarily used for drilling faucet mounting holes in stone countertops or plumbing lines in showers and vanities. Marble hollow drill bit long lasting. Made of high carbon steel, piercing quickly and precisely with long life. High carbon steel blade sharp and smooth. Small incision resistance, stably piercing for clean and smooth opening, not breaking the edge. Golden coating for durability. Diamond coated hole saw has golden coating to prevent rusting. Features Material: High-grade carbon steel Size: 70 mm in diameter Package includes: 1 x Diamond hole saw bit Suitable for glass, ceramic tiles, porcelain tiles, marble, granite, reinforced concrete and other hard materials. Compatible with hand drill, bench drill. Note: Keep water or lubrication to cool the tool, which will prolong its life.