RNK111
https://www.rnktools.com/products/step-drill-bit.html
According to the need to process different diameters of holes, and can achieve large holes in one-time processing, without the need to replace the custom step drill bits and playing positioning holes and so on. On the forming workpiece of step parts, multiple step holes are processed by one-time forming drilling, composite forming, fast and time-saving. High efficiency, saving non-processing man-hours. Use special equipment to grind and process, high precision. Adopting high quality alloy bar, good wear resistance.