【Torsion resistance】The universal triangular shank can effectively prevent slippage and withstand more torque. 【Drilling】The hole opener can be used on drill presses, workbenches, hand drills and drills, but not impact drills (cannot be opened by the impact function). 【Note】Place at an oblique angle of 45° and drill at the vertical (note that the speed can not be too fast, and the speed should be operated slowly at about 800-1000 rpm). 【Application】Suitable for all types of stone, ceramic , glass, glass, etc., follow the addition of water to cool the holes. 【Chip removal】The opener adopts a segmented design, which has low cutting resistance and is conducive to chip removal. Number of pieces delivered: 1 Size: 90 mm lucky