[quote name='smthng']Also, any decent farm store or auto parts store should have more varieties of u-bolts than you could imagine. After you've snugged ubolts, you can always cut off excess thread with bolt cutters, dremel, hacksaw, etc.[/QUOTE]
Washers and nuts, double nut the side coming out of the wood. Be careful if you cut the threads, if you screw it up you may have a hard time getting the nuts off and not be able to get them back on. A dremel to make a real nice flat cut would be ideal. You could also use vinyl tubing to cover the threads if you're worried about scratches or snags.