CHIP REMOVAL HOLE DESIGN:All specifications have special holes for chip removal, and all debris generated when you drill is very easy to discharge. DRY GRINDING IS STRICTLY PROHIBITED:This hole saw cannot be dry ground, so you need to constantly adding water to cool in the process of drilling. MEET YOUR DEMANDS:Great hole saw is suitable for drilling on tile,concrete, brick, glass, marble, ceramic and etc. EXCELLENT TRIANGLE DRILL SHANK:Universal triangle drill shank effectively prevents slipping during drilling and withstands greater torque. INTIMATE TIPS:The hole opener can be used on bench drill, power drill and machine tools with drilling function but not for impact drill (Cannot use the impact function to drill). Specification: Item Type: Hole Saw Drill Bit Optional Style: 40mm, 45mm, 50mm, 55mm, 60mm Opener Specifications:40mm / 1.6in, 45mm / 1.8in, 50mm / 2in, 55mm / 2.2in, 60mm / 2.4in Total Product Length:83mm / 3.3in, 83mm / 3.3in, 84mm / 3.3in, 84mm / 3.3in, 80mm / 3.1in Handle Length:25mm / 1in, 25mm / 1in, 25mm / 1in, 25mm / 1in, 25mm / 1in Handle Diameter:9.4mm / 0.4in, 9.4mm / 0.4in, 9.4mm / 0.4in, 9.4mm / 0.4in, 9.4mm / 0.4in Working Depth:58mm / 2.3in, 58mm / 2.3in, 58mm / 2.3in, 58mm / 2.3in, 58mm / 2.3in Package List: 1 x Hole Saw Drill Bit Note: Position at an oblique angle of 45 first, and drill the hole vertically(note that the speed should not be too fast, and the speed should be slowly operated at about 800-1000 rpm)