In our 30 years of selling tooling we have used CBN in many applications.  CBN is used in the OEM market for roughing cast iron parts such as brake rotors, cylinder heads, blocks and any other cast iron parts that needs stock removed quickly and with long tool life.  Depths of cut at .080" and feed rates of .025" per revolution are common.  We've found that when using our "CHIP THICKNESS CHART" we can coach customers to maximize chip thickness for particular speeds and depths of cut.  LET US HELP!