Insert GradesSteelStainlessSteelCast IronExotic AlloyHardene dNon-FerrousSteelMetalFor SmallLathes WorkDepth of Cut ap (mm) MaterialCutting Speed Vc (m/min) LargeDepth of Cut RoughingMedium CuttingFinishing Cutting Speed Vc (m/min)Depth of Cut ap (mm) LargeDepth of Cut RoughingMedium CuttingFinishing Chipbreaker and Grade Selection Guide for Turning Cast Iron Cast Iron Grades Coated SUMIBORON SUMIBORON Solid SUMIBORON BNC500 BN7000 BNS800 L7 ● FC (Gray Cast Iron) ● FCD (Ductile Cast Iron) 2,000 500 A 1,000 BN7000 High-speedContinuous CuttingAC4010K BNS800 300 Our 1st recommended gradefor machining cast iron High-speed500Continuous Cutting AC4015K AC4010K BNC500 200 300 Our 1st recommended grade Mill-scaled200for machining cast ironWork/Interrupted Cutting Mill-scaled Work/Interrupted Cutting AC4015K AC420K AC420K 100 AC8025P 100 AC8025P Finishing Roughing Finishing Roughing Continuous Partially Interrupted Interrupted Continuous Partially Interrupted Interrupted Chipbreakers Negative Type Positive Type 6.0 No Chipbreaker ME Type ME Type NoME TypeChipbreaker 6.0 4.0 UZ Type GU Type GZ Type GZ Type 4.0 No No Chipbreaker GZ Type Chipbreaker MU Type MU Type 2.0 GU Type UZ Type 2.0 MU Type GU Type UZ Type 0 0.2 0.4 0.6 Sharp Edge Strong Cutting Edge 0 0.2 0.4 0.6 Sharp Edge Strong Cutting Edge Feed Rate f (mm/rev) Feed Rate f (mm/rev) Recommended Cutting Conditions Cast Iron (Red text indicates 1st recommendation) Work Material Cutting Process Grade Cutting Conditions  Min. - Optimum - Max. Depth of Cut ap (mm) Feed Rate f (mm/rev) Cutting Speed vc (m/min) High-speed BN7000 0.1 - 0.3 - 1.0 0.10 - 0.20 - 0.50 500 - 1,500 - 2,000 Gray Cast Iron Continuous to General AC4010K 0.5 - 2.0 - 6.0 0.10 - 0.25 - 0.40 200 - 400 - 700 (FC250, etc.) Interrupted AC4015K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.50 180 - 300 - 450 Heavy Interrupted AC420K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.60 150 - 200 - 300 High-speed BNC500 0.1 - 0.2 - 0.5 0.10 - 0.20 - 0.40 150 - 350 - 500 Ductile Cast Iron Continuous to General AC4010K 0.5 - 2.0 - 6.0 0.10 - 0.25 - 0.40 180 - 300 - 450 (FCD450, etc.) Interrupted AC4015K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.50 160 - 250 - 400 Heavy Interrupted AC420K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.60 120 - 170 - 250 High-speed BNC500 0.1 - 0.2 - 0.5 0.10 - 0.20 - 0.40 200 - 350 - 500 High-strength Ductile Continuous to General AC4010K 0.5 - 2.0 - 6.0 0.10 - 0.25 - 0.40 160 - 250 - 400 Cast Iron(FCD700, etc.) Interrupted AC4015K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.50 140 - 200 - 350 Heavy Interrupted AC420K 0.5 - 2.0 - 6.0 0.10 - 0.30 - 0.60 80 - 150 - 220 A16