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 circlesLong life: heavy-duty hole saws provide superior performance, durability is more 8 times than other common diamond hole sawsAttention: 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 youProductFeatures:Material: Carbon Steel carbon.Shank diameter: 10mm.Diamond coating: 1.5mm.Features:This drill bit diamond removes a full circle from glass, tile, marble, granite, ceramic or other materials.Caution:Always use water for cleaning. lubrication, otherwise the diamond drill bit will burn out.Can be used with a standard electric drill.Make a half round mark at a 45 angle and then hold the drill straight.Reduced drill speed, low drill pressure and increased use of water to keep hole saws cool will significantly extend drill bit life.