Diamond hardness and wear resistance are extremely high, its microhardness can reach 10000HV, which is the hardest material in engraving tool materials. The friction coefficient of diamond is small, it has no affinity with non-ferrous metals, the chips are easy to flow out, the thermal conductivity is high, the built-up edge is not easy to be formed during cutting, and the surface quality is good. Can effectively process non-ferrous metal materials and non-metal materials, such as copper, aluminum and other non-ferrous metals and their alloys, ceramics, unsintered hard alloys, various fiber and particle reinforced composite materials, plastics, rubber, graphite, glass And a variety of wear-resistant wood (especially composite materials such as solid wood and plywood).

The disadvantage of diamond is poor toughness and low thermal stability. It is easy to carbonize when it is 700 °C ~ 800 °C, so it is not suitable for processing steel materials. Because at high temperatures, iron atoms easily interact with carbon atoms to convert them into graphite structures. In addition, when used to machine nickel-based alloys, the tool wears out quickly.

The hardness of cubic boron nitride (CBN) is second only to diamond, the hardness can reach 8000HV～9000HV, and the thermal stability is high (up to 1250°C～1350°C). It is chemically inert to iron elements and has strong anti-bonding ability. It can be ground with a diamond grinding wheel, so it is suitable for processing all kinds of hardened steel, thermal spray materials, chilled cast iron and cobalt-based and nickel-based hard-to-machine materials with hardness above 35HRC.