Feature1Supports diamond coating and washable nickel surface, such drill bit can be easy to use in the practical life.2On the one hand, diamond coating increases the drilling speed, making it the sharpest drill bit. On the other hand, nickel-plated surface can extend the life of the drill bit and improve its corrosion resistance.3To drill glass, cookie jars, bottles, tiles, fiberglass, ceramics, marble, slate, and granite, this drill bit is suitable for forming clean and accurate holes in glass and tiles Use under.Do not use on concrete or in depths longer than 1/2 inch.4All drill bits are coated with a smooth and accurate coating. Reducedrilling speed, lower drilling pressure and increased use of water lubrication will greatly extend the life of the drill bit.5Keeps long service life, hole saw bit with high quality and high performance is very fit for making clean and precise holes.Item Type: Drill bitColor: SilverMaterial: High speed steelHeight: Approx. 50mm / 2inDiameter: Approx. 8mm / 0.31in, Approx. 10mm / 0.39in, Approx. 14mm / 0.55in, Approx.16mm / 0.63in, Approx.18mm / 0.71in, Approx. 22mm / 0.87in, Approx. 26mm / 1.02in, Approx. 38mm / 1.5in, Approx. 45mm / 1.77in, Approx. 50mm / 1.97in Package List10 x Drill Bit