[Porchdog]

Aschen is correct - the Oxide layer is very thin and the bare alloy under pressure welds easily.

We are forced to use stainless nuts and bolts in a lot of situations (food and Pharma). Using 18-8 nuts can help. Stainless grade anti seize is a must. If they are acceptable I always spec. copper alloy nuts.

For auto applications I use high strength non stainless fasteners. These have enough alloy in them to minimize corrosion and they don't gall.

Deformed stainless lock nuts are one time use at best.