1、Diamond Coating: Our open hole drill bit's diamond coating increases the drilling speed and sharpness of the drill bit. Electroplated diamond is uniform and more wear resistant. 2、100mm Specification: Diamond hole saw bit size is 100mm or 4in, you can install and use it according to the actual situation. 3、Clearance Hole: The diamond hole saw bit has a clearance hole that facilitates the entry of cooling water and the removal of chips from the hole. 4、Nickel Plated Surface: This diamond hole saw drill has a nickel plated surface for longer life and improved surface corrosion resistance. Improves performance and maintains a sharper cutting edge. 5、Applicable Materials: Diamond hole saw bit makes the drilling process easier. Suitable for ceramics, tiles, limestone, slate, marble, light stone and fiberglass.