Search our quarter-million Q&As

Home of the finishing HOTLINE since 1989

-----

How to provide corrosion protection on automotive cast iron brake rotors?

I'm a retired automotive brake design engineer and just starting in the consulting business on my own. I am wondering if cast iron can be "blued" like done on gun barrels? Since automotive wheels are being designed with larger openings, the disc brake caliper and rotor are seen more and subject to rusting before being delivered to the buying customer. I'm wondering if a blued rotor would be feasible on a high volume production basis and what sort of process would be required to do this? Right now this is somewhat of an academic inquiry.

John F. (Jack) Limberg
- Granger, Indiana U.S.A.
2000

Jack - Yes it is possible to to "blue" (actually blacken) a cast iron part. The chemistry is pretty similar to black oxiding stainless steel, and could be done with a rack system to handle production runs. The drawback would be the eventual wear of the black, since it is only as hard as the part - ergo, if a brake pad can wear down the rotor, it can wear off the coloring (although the oxide coating does penetrate into the iron). If you want more info, go to our website and look at Black Magic SS-C.

Dan Brewer
chemical process supplier - Gurnee, Illinois
2000

Sorry! Finishing.com is temporarily Read-Only.
Ted Mooney is retiring but I have several offers to take it over.
We're working hard to make sure we find it the best new home.

---

---