CBN is an extremely hard tool material second only to diamond. It has higher impact strength and fracture resistance than ceramic tools, and it can also cut hard metals for lower rigid machine tools. Furthermore, a properly customized CBN tool can withstand the cutting load of high-power rough machining, as well as the heat and wear properties required for the impact of interrupted cutting and fine machining. The material with high CBN content is used for rough machining of hardened steel and pearlitic gray cast iron, and the material with low CBN content is better for hardened ferrous metal machining. Because CBN tools can obtain better and concentricity.