escription Size: Hole diameter: 1/2 inch(13mm), Shank diameter: 0.25 inch(6.5mm), Drilling depth: 1.18 inch(30mm), Total length: approx. 1.97 inch(50mm). Package includes 10 pcs diamond hole saw drill bits.. Diamond Coated: The drill bit is designed with diamond coating, which improves the drilling speed, makes the drill bit more sharp and durable, and wear-resistant. The diamond hole saw is made of steel material, not easy to rust.. Side Hole Design: The side open can remove the waste, debris can be quickly removed when opening the hole, keeping the drill bit clean, and dissipating heat.. Widely Used: The diamond coated drills are perfect for drilling glass, tiles, ceramics, porcelain, slate, marble, limestone, etc, removes a complete circle.. Tips: When the glass drill bit is working on the glass or tiles, please use lubrication (water) and drill slowly, which will extend drill bit life..