Hardened Steel Machining
Precision Cast Iron Machining
Application Examples
Roll Turning
Valve Seat Machining
Heat Resistent Alloy Machining


FAQ's for CBN (BN500, BN600 & BNS800) on Cast Iron machining
Kindly click on the arrows to view the answers
Expand/Collapse ItemQues: Why CBN tools for Cast Iron Machining?
Answer: Cast iron material being highly abrasive in nature with high content of carbon in form of graphite makes the hardmetal (Carbide, coated carbide) tools wear quite fast & CBN being most wear resistant material (exceeded in hardness only by diamond) gives excellent surface finish, increases the productivity by reduction of cycle time & tool change frequency/time, able to machine components with close tolerance consistently when applied to CI finishing applications.
Expand/Collapse ItemQues: What are the characteristics of CBN, which makes it Ideal for Cast Iron Machining?
Answer: CBN is the hardest material recommended for cast iron machining. Its property of excellent thermal conductivity & thermal resistance make it ideal for CI machining at higher speed when the temperature of machining goes higher & other tool materials fail.
Expand/Collapse ItemQues: What is benefit one can get by using CBN at Cast Iron as compared to conventional Hardmetal grades?
Answer: CBN usually gives life of 15 to 50 times, finish achievable up to Ra 0.6 ~0.8 m & Tolerance up to class 6~7 is achievable quite consistently. CBN also can be used at a speed range of 200~2000mtr/min by which reduction in cycle time or increase in productivity is possible.
Expand/Collapse ItemQues: Is CBN recommended for Cast Iron Milling also, if yes what are the benefits & its limitations?

Answer: Yes, CBN can be applied for finish milling of cast iron with BN Finish Mill & BN 600 Inserts. It can achieve a surface finish of Rmax 3.2 (Apx. Ra 0.8m) better flatness, good productivity & reduction in tool change time. Cylinder Block & head, Transmission case Machine-housing joining faces & machine bed is the ideal application for it. The conditions for BN Finish mill are speed 800~2000Mtr./min, absolute dry condition, & depth of cut less than 0.5mm.

BNS800 (new solid CBN grade) inserts can be used for general milling of cast iron also for the conditions Speed800~2000mtr./min, depth of cut up to 4mm & federate 1.0mm/rev. max.

Expand/Collapse ItemQues: CBN for Cast Iron Machining should be used in dry or wet condition?

Answer: We recommend using of soluble coolant always in continuous or interrupted turning for cast iron machining with CBN grades of BN500 & BN600. Whereas we recommend absolute dry condition for Cast Iron Milling with BN Finish Mill & BN 600 grade. Also with new solid CBN Grade BNS800 one can machine Cast iron in both dry & wet condition.

Expand/Collapse ItemQues: Can we use CBN for CI finishing at a speed less than 200mtr./min?

Answer: CBN tools can be used at a lower speed also, but the cutting forces are much higher at a speed less than 200mtr./min cutting force gets stabilized at a speed near to speed of 200mtr/min. So is the surface finish, it is very difficult to get good surface finish for which CBN tools are used for Cast Iron machining at speed less than 200mtr./min.

Expand/Collapse ItemQues: What is the Grade & cutting Conditions recommended for SG or Nodular Cast Iron?

Answer: We recommend to use BN 500 Grade for SG or Ductile Cast Iron for continuous or interrupted turning in wet condition at a speed range of 150~350mtr./min. We also recommend the use of BNX10 for continuous turning at a speed range of 250~500mtr./min.

Expand/Collapse ItemQues: What are the usual components & applications where CBN tools are used?

Answer: All the component made of CI where fine finish, close tolerance & high productivity is desired CBN can be the ideal selection e.g. precision bearing bores, Cylinder Block liner or parent bore, Flywheel boring, Brake Disc facing, face milling of Cylinder Block & Head where fine finish & flatness is desired.