Why it's not recommended:
Galvanic corrosion:Stainless steel and galvanized steel (zinc-coated steel) are different metals, and their combination can create a corrosion cell. The zinc coating on the bolt will corrode more quickly when in contact with stainless steel, especially in a wet or salty environment.
Fit issues:
Galvanized bolts typically have a slightly different thread pitch than plain bolts, and using a plain stainless steel nut on a galvanized bolt can cause galling or stripping of the threads.
Alternatives:
Use galvanized nuts and washers with galvanized bolts: This is the ideal combination for a durable and corrosion-resistant joint.
Use stainless steel bolts with stainless steel nuts and washers: This ensures a compatible and long-lasting connection.
Consider using non-metallic barriers: If you must use dissimilar metals, you can use a nylon or rubber washer or other non-conductive barrier to isolate the metals and reduce the risk of galvanic corrosion.
When it might be acceptable:
In dry environments:In dry environments where there is no moisture or electrolyte, the risk of galvanic corrosion is significantly reduced.
For short-term use:
If the connection is only temporary, the risk of corrosion might be minimal.
In summary, while it might be tempting to use stainless steel nuts on galvanized bolts, the risk of corrosion and fit issues usually outweigh the benefits. It's best to use the same type of metal for both the bolt and the nut when possible, or to consider using non-metallic barriers if necessary.
