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Blackening treatment for 316 Stainless

2004

I currently manufacture a line of 316L Stainless fasteners that I will be required to produce with a black finish. I am resistance welding the product and have tried black oxide finished material, but the oxide comes off during the welding process and deposits on my electrodes causing weld failure. I am looking for a black finish that is not prone to coming off and the finish needs to be applied to a 20-30 lb. coil of the 316L wire. I have heard that the passivation process that can generate this result, and have read that this is sometimes done on accident, and is called "flash attack". Do you know if companies are doing this blackening as a standard process, and would you be willing to share this information?

Thank You,

Doug Saunders
Fastener Manufacturing - Grand Rapids, Michigan

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adv.
We have an electrochemical environmentally friendly room temperature blackening process for zinc surfaces. This is in tune with the process you are talking about. We will be happy to develop a process for stainless steel that will meet your requirement. Please contact us.

Ravi Chandran, Ph.D
New Brunswick, New Jersey
2004

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I think the best solution for you is to weld the parts prior to blackening.

Tim Hamlett, CEF
- West Palm Beach, Florida, USA
2004