The authoritative public forum
  for Metal Finishing since 1989
  

  -----

Black hard coat for mild steel?

2003

I'm looking for an inexpensive way to finish mild steel parts with a satin black wear surface. I don't want to dimensionally change the parts and temperatures must be kept low enough as to not distort them. This is for rotational joints on automation equipment where a tube has its OD running inside a double lip seal. Rotational speed is 60 RPM max. Tube ODs range from 45mm to 100 mm. I have used products from a hydraulic supplier that uses what they call black hard coat (or BHC) on the exterior of their steel components. This type of finish looks like it would work well for my application. Does anyone know of anything like this? I haven't been able to find anything on the web and don't want to ask them for what is probably proprietary information.

Thanks,

David Bernier
- Swanton, Vermont, US

---

There is no law forbidding salespeople from making up any name they like, so the only authority on what BHC actually means may be the company that calls their finishing BHC. And it could be one thing this month, and another thing next month. But it is very common for parts like this to be black oxided.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003