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Wear Resistant Corrosion Protective Coating

I need a wear resistant corrosion protective coating for a threaded fastener. The current fastener with a corrosion protective coating tends to strip the coating when the nut is tightened on the fastener allowing the threaded section to corrode in service. I need about 150 hours of salt spray protection in the assembled state. Any low to moderate cost ideas?

Steven M. Johnson
automotive - Livonia, Michigan, USA
2000

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It would be nice to know what your current coating is that is cracking/failing. Assumption 1- Electroless Nickel costs more than you want to pay. Assumption 2-You do not want to paint it after assembly.

I would look at tin- zinc alloy. It is fairly soft or malleable, so should "give" like cadmium. Nickel- zinc and cobalt- zinc are quite a bit harder, but might work, and are a lot more available from jobshops.

James Watts
- Navarre, Florida
2000

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You do not say what type of coating you are using now and what results you are getting. You might want to look into topcoats that contain lubricants that would lower the coefficient of friction when you torque the nuts down so you do less damage to the coating.

George Shahin
Atotech - Rock Hill, South Carolina
2000

We plate hundreds of thousands of fasteners a week, and many different finishes would fit the salt spray requirements you mention.

Brian Lucas
plating shop - Thomaston, Connecticut
2000