Use a little anti-seize on the threads to prevent galling. I learned about this phenomena the hard way when bolting an ISO flange together. The nut/bolt was still loose on the flange but the nut kept getting tighter even though there was still a lot of travel left. I then tried to back it off and it got even tighter! Had to use a grinder to get the bolt off and started over using a little anti-seize (aka, personnel seeking compound because it gets everywhere).
I think the stainless hardware supplied with the Trailex trailer is aluminum or tin plated to do exactly this without the mess.
-Bob