ceramic inserts are suitable for turning and milling all kinds of hardened steel HRC58-65,hardened ceramic inserts are suitable for turning and milling all kinds of hardened steelHRC58-65,hardened cast iron HS80-90,high Managing steel,Ni-Cr alloy,cast iron,allkinds of nonmetallic materials,plumbago,vitreous steel and fireclay insulatingrefractory.