Cubic boron nitride (cbn) and polycrystalline cubic boron nitride (pcbn) tool has been widely used for hard material such as turning. But there are still many plant, because their prices are too high and refused to choose. Using a new cryogenic cooling technology, you can not use expensive high-speed hard drive machining tools, and also to extend tool life. By American air products developed icefly type cryogenic cooling system, the hard drive can, the -320 ° f liquid nitrogen, injected directly into the knife head through a nozzle. The working principle is based on the injection of liquid nitrogen into the knife head, can rapidly reduce the high cutting temperatures generated in the cutting area, reducing the softening effect of the tip due to high temperature, increase hardness and cutting tool cutting head. In addition, more of the most significant is processed at low temperature cooling, can better protect the integrity of the cutting edge, to prevent damage to the cutting edge of the machined parts breakage caused. While the processing parts surface showing compressive stress, improve the surface quality of machined parts and reduce the surface roughness. air products company's cryogenic cooling system, can be used as a standalone system or assistive devices the machine cooling system, a variety of tools to transform. As hardinge company (in Elmira, New York City) produced quest series lathes. It is generally stored in liquid nitrogen near the machine cylindrical container or in a sealed tank. Via a universal joint of the connector has a flexible pipe with liquid nitrogen lathe tool holder connected via a liquid nitrogen delivered to the nozzle tip. Use the same procedure for the preparation and the conventional cooling system. According to reports, the cryogenic cooling system for machining hardened steel parts, hard composite materials and powder metallurgy, and more particularly having a good advantage. That is because the inert liquid nitrogen after contact with these parts, you can quickly muddy hair, and not as usual on the part left left remnants. This is particularly useful parts of powder metallurgy processing similar porous materials, saving extra material generally needs to be carefully cleaned of time.