pcbn inserts in solid cbn and tipped cbn for hard turning of cast PCBN inserts for turning cast iron and hardened steel: pcbn is the second hardest material in the world, and cbn related high precision cutting tools are introduced to industry, achieved high productivity and cost reductions. pcbn is the short name of polycrystalline cubic boron nitride, and pcbn inserts are mainly for the hard metal turning to replace the conventional machining way Stanford University UNK the , . of and in " a to was is ) ( for as on by he with 's that at from his it an were are which this also be has or : had first one their its new after but who not they have shape C diamond shape (80 degree) - pcd insert tipped pcd inserts in 80 degree diamond shape C for hard turning non-ferrous metals of aluminum, the pcd insert cutting edges are made with polycrystalline diamond, indexable inserts with pcd working tips are precision cutting tools, which are used in cnc super fine finish machining, turning and milling automobile engine block, cylinder head, gearbox, cast aluminum alloy with