Diamond Drill Bit: made of carbon steel with diamond coating for porcelain, glass, marble, ceramic, stone and granite etc. High Quality Hole Drilling: thick blade with brazed design for long life. Ideal for drilling clean, precise holes and cutting perfect circles Long Lifespan: Heavy duty hole saws offer superior performance, durability is 8 times higher than other traditional diamond hole saws Caution: Start drilling at 45 degree angle and drill vertically when the half moon edge is cut to prevent the hole saw from slipping. Never let your drill dry out and use water to keep it moist and cool. What makes us different: Our goal is to make the best products to inspire our customers to live a healthier, convenient and safe lifestyle. We have a professional product monitoring team that focuses on every detail that matters to you Product Description Features: Material: Carbon steel, carbon. Shank diameter: 10mm. Diamond coating: 1.5mm. Features: This diamond drill bit removes a complete