The only SS nuts and bolts of the same grade being used together that I have seen are the ones made from Marine grade SS. The grade 316 appears to work ok. The same grade may fail if the nut is tensioned and released (ie, unloaded) on a regular basis. What happens is that the surfaces of the threads sieze up big-time! The threads basicly weld themselves together and they do an excellent job of this. Lubrication does help but it's not a permanent fix.
If you use SS nuts and bolts on your boat or yacht, you wont have any problems other than corrosion. SS bolts on boats are usually left tensioned up and are not undone over and over. If you have SS bolts holding fittings (winches etc.) through a wooden deck or rail, corrosion will be your biggest worry. I have seen 3/8 SS bolts corroded down to 1/8" dia where they passed through the timbers. The nut, end of the threaded bolt and the hex head were in perfect condition. This is a common problem with SS bolts. The material corrodes when free oxygen is unable to reach the SS. There are much better and far stronger materials for corrosion resistance available for about the same cost or not too much more.
My trainees discovered that SS does not make a long lasting component if threaded sections are continually undone; the very reason why I chose this material to be used for this project.
Hope this helps you
Joe
