Diamond drill bit: made of carbon steel with diamond coating for porcelain, glass, marble, ceramics, rock and granite, etc. High quality hole drilling: blade thick with a brazed design for long life, ideal for drilling clean, precise holes and cutting perfect circles Long life: heavy-duty hole saws provide superior performance, durability is more 8 times than other common diamond hole saws Attention: Start drilling at a 45 degree angle, and drill vertically when the crescent-shaped edge is cut to prevent the hole saw from slipping. Never let your drill bit dry out and use water to keep it moist and cool. How we're different: We aim to make the best products to inspire our customers to live a healthier lifestyle. convenient and safe. We have a professional product monitoring team who focus on every detail that matters to you Product Description Features: Material: Carbon Steel carbon. Shank diameter: 10mm. Diamond coating: 1.5mm. Features: This drill bit diamond removes a full circle