Cubic boron nitride (c-BN) was first synthesized by General Electric (GE) in the 1950s using artificial methods under high temperature and high pressure conditions. Its hardness is second only to diamond and far higher than other materials, so it is referred to as superhard materials. Superhard materials are widely used in sawing tools, grinding tools, drilling tools and cutting tools. Diamond is easy to be oxidized at high temperature, especially with good affinity with iron-based elements, so it is not suitable for iron-based element ferrous metal processing. The crystal structure of cubic boron nitride is similar to that of diamond, and its hardness is slightly lower than that of diamond. It is often used as abrasive and tool material. In 1957, R.H. Wentoff of the United States first developed cubic boron nitride, but so far no natural cubic boron nitride has been found.

The properties of cubic boron nitride mainly include high hardness and thermal stability, and its microhardness is second only to artificial diamond. Its thermal stability is better than that of artificial diamond, and it can still maintain high mechanical properties and hardness at high temperature, and has good red hardness. Besides, it has stable structure, high oxidation resistance, and good chemical stability, which is much better than diamond.  It does not chemically react with iron group elements at temperatures as high as 1100~1300 ℃, so it is especially suitable for processing ferrous metal materials. The thermal conductivity is smaller than that of diamond, but higher than that of cemented carbide. And it has high bending strength. As abrasive material, it has long service life and good wear resistance. However, single crystal cubic boron nitride has a small grain size, anisotropy, and a cleavage plane that is easy to split, and is brittle and prone to cleavage damage.