Feature: 1. DIAMOND COATING: The diamond hole cutter is made of carbon steel, with diamond coated hole saw bit, extremely sturdy and durable 2. SUITABLE FOR A VARIETY OF MATERIALS: Can be used for porcelain, glass, marble, ceramics, rock and granite, etc. 3. GOOD QUALITY DRILLING: Thick blades with brazed design, very suitable for drilling clean and accurate holes and cutting perfect circles 4. LONGER SERVICE LIFE: Heavy duty hole saws have superior performance and durability than other ordinary diamond hole saws 5. 35MM PUNCHING DEPTH: Of sharpness cutter head bring fast drilling speed, punching depth up to 35mm, useful and practical Specification: Item Type: Diamond Drill Bit Material: Carbon steel + diamond coating Punching Depth: Approx. 35mm / 1.38in Handle: Triangular handle. Package List: 1 x Diamond Drill Bit1 x Storage Box Note: Start drilling at a 45 degree angle, and drill vertically when the edge is cut to avoid the hole saw from slipping. Never let your drill bit run dry, use water to keep wet and cooling.