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  for Metal Finishing since 1989
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Gold Adhesion on Work Hardened Area Different

I am a spring designer of miniature probe springs that get plated with gold. We are having a problem with the gold plate's adhesion and being a very thin gold plate on one specific area of the spring. This area is in the inner diameter and coincides with where the tool contacts. The tool and wire get very hot,(red hot), due to friction. I believe this is hardening this area. My question is: If a small area of a piece of metal, (type 302 Stainless steel), is much harder than the rest of the part, which was caused by local area heating, will the gold plate be thinner with less adhesion?

Thank you,

Gary Eastman
Designer - Farmington, Connecticut, USA
2004

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302 ss steel requires a nickel strike, gold strike and then gold plate. This is the only way to get satisfactory adhesion on 302 stainless. The heat treat may cause scale that must first be removed before starting the plating cycle above, thickness of gold is determined by the number of ampere minutes in the plating solution, not by any heating treatment.

Don Baudrand
Consultant - Poulsbo, Washington
(Don is co-author of "Plating on Plastics" [on Amazon or AbeBooks affil links]
           and "Plating ABS Plastics" [on Amazon or eBay or AbeBooks affil links])
2004

There are proprietary gold strikes made for plating directly onto stainless steel substrates. They work very well and have outperformed woods nickel strikes in certain applications. Ask your gold supplier if they have a SS Gold Strike, or maybe its time to do some shopping!

Rick McCarthy
- Chicago, Illinois, USA
2004