
Chipbreaker and Grade Selection Guide for Turning Material Cast Iron Work Cast Iron Grades Coated SUMIBORON SUMIBORON Solid SUMIBORON BNC500 BN7000 BNS800 L7 ● FC (Gray Cast Iron) ● FCD (Ductile Cast Iron) Insert Grades 2,000 500 A 1,000 High-speed BN7000 Continuous Cutting AC4010K Cutting Speed Vc (m/min) Cutting Speed Vc (m/min) Our 1st recommended grade BNS800 300 for machining cast iron High-speed 500 Continuous Cutting AC4015K AC4010K Steel BNC500 200 300 Our 1st recommended grade Mill-scaled Mill-scaled Work/Interrupted Cutting 200 for machining cast iron Work/Interrupted Cutting AC420K Stainless AC4015K AC420K Steel 100 AC8025P 100 AC8025P Cast Iron Finishing Roughing Finishing Roughing Continuous Partially Interrupted Interrupted Continuous Partially Interrupted Interrupted Exotic Alloy Chipbreakers Hardened Negative Type Positive Type Steel Roughing Roughing 6.0 No 6.0 No Chipbreaker ME Type ME Type Chipbreaker Large Large ME Type Depth of Cut ap (mm) Depth of Cut ap (mm) Non-Ferrous No Chipbreaker Medium Cutting Medium Cutting Metal 4.0 UZ Type GU Type 4.0 GZ Type GZ Type No GZ Type Chipbreaker Depth of Cut Depth of Cut MU Type MU Type 2.0 GU Type UZ Type 2.0 MU Type Finishing Finishing GU Type For Small Lathes 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) Cast Iron Recommended Cutting Conditions (Red text indicates 1st recommendation) Cutting Conditions Min. - Optimum - Max. Work Material Cutting Process Grade 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