COMBINING STAINLESS AND CARBON STEEL MEMBERS

[bassonet]

We are assembling a structure made up of a combination of stainless and carbon steel members. What is the best practice of bolting together (using isolating packers or gaskets) and what bolts to use (Zink plated?)?

 

[Duwe6]

You got it exactly. Some kind of non-compressible spacer between the faying surfaces, and galvanized bolting.
Wouldn't hurt to have a s/s washer on the galv bolt/nut on the stainless side of the joint.

The 'spacer' can be good, well cured paint [heavy and/or partially cured paint oozes and releases the bolt tension]. Another good choice is using stainless "finger shims" or pre-punched thin plate between the members. Or you can just hot-dip galvanize the carbon steel members.

 

[MikeMet]

Let's not get too complicated here for no reason. Unless your component is going to be wet all the time or submersed, don't worry too much about galvanic attack. If there is a fire danger I would not use galvanized componets due to possible LME from molten zinc. If no fire danger, and not wet or submersed, simply bolt together.