CNC Indexable Tipped PCBN Diamond Insert Turning Tool Inserts. Application: solid CBN inserts are used for rough and fine machining cast iron, grey cast iron, brake disk, roller, high nickel-chromium, super finishing of Hardened Steel, Chilled Steel, Bearing Steel, Die Steel Gauge Steel, Tool Steel, High Steel, etc. continuous and interrupted turning HRC50-64,powder metallurgy work-piece,thermal spray coating work-piece etc.