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  for Metal Finishing since 1989
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Fastening stainless steel to carbon steel

I have a condition where I need to attach stainless steel sheet metal to galvanized carbon steel furring. The furring may be treated with an inorganic zinc coating. I plan to provide a separation between the stainless steel sheet and the furring to prevent any type of reaction between the dissimilar metals, however I still need to fasten the stainless steel sheet with a fastener that will not react with the carbon steel or with the stainless steel. I was planning to use 316 stainless steel fasteners, is there anything that you can recommend that would be better than the stainless?

Kenneth Paquette
- Melbourne, Florida, USA
2003

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Depending on the structural strength needed, it may be best to use plastic fasteners for this. You can purchase a variety of excellent fasteners of polypro, Teflon (TM), etc. You could always use a few extra plastic fasteners.

If you need the structural strength of metal for the fasteners, the 316 ss would be okay. The galvanic effect would still be there, but the fastener itself should survive. The corrosion, if it occurs would probably be on the zinc/carbon steel side.

Lee Kremer
Stellar Solutions, Inc.

McHenry, Illinois

2003

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2003

Kenneth,

What Lee suggested is right on! However, you didn't say much or anything about the type of fasteners or the strength required. This is a common complaint as readers imagine that we repliers are mind readers and omniscient, which we sure ain't!

Consider some stronger plastics. There's a whole range of nylon nuts-n-bolts and some glass filled Polyurethane bolts which used to run under the trade name of Aickenstrut.

Your idea of the separation between the sheets is l00% correct! On large flanges, in order to save $, I'd use m.s. bolts and s.s. nuts (along with some moly graphite grease) and had ne'er a problem.

Freeman Newton [deceased]
(It is our sad duty to advise that Freeman passed away
April 21, 2012. R.I.P. old friend).