CBN  cutting tools is the best choice for high speed and precision machining of high-hardmaterial difficult-to-cut material and cast iron.
the main benefits of using CBN tooling for hard part turning include

1.  Longer tool life
2.  Higher material removal rates
3.  Reduced machine downtime
4. INcreased productivity
5.  BEtter surface finish

Grade MRN600:Machining normal gray cast iron with high speed, like engine cylinder and cover etc.
Grade MRN620:Machining alloy cast iron and alloy cast steel, like roller, slurry pump and mine machines etc.
Grade MRN680:Machining wear resistant alloy cast iron with high speed, like brake disc and brake drum etc.
Grade MRN900:Machining some tough materials, like hardened steel, bearing steel and die steel, high speed steel etc.

Application:
Workpiece:Chilled Cast iron Roll
Hardness:HRC55-65
Machining type:Roughing
CBN Insert:RNMN201000 MRN620
Cutting Type:Dry cutting
Cutting parameters:Vc:40-60/min Ap:4-6mm Fn:1.5-2.5mm/r 
Tools life:1pcs/cutting edge