This is a tool material, in which fine crystals of cubic boron nitride--the hardest material next to diamond--is tightly compacted and sintered on the cemented carbide base using special binder under high temperature and high pressure. The hardness is more than twice that of cemented carbide, with the hardness at high temperature exceeding that of cemented carbide. cBN has no tendency to react with ferrous materials (which is different from the case with diamond), and thus suitable for high-speed cutting of cast iron, finishing of hardened steel, cast iron, ferrous sintered metals (valve seat, etc.). This material is also suited for finishing of super heat resistant alloys. The use of cBN sintered material enable the finish surface accuracy (expected only through grinding up to now) simply by cutting.
