[Zeke]

Grade 8 bolts, Nyloc nuts and washers. I use S hooks to hang tools. I don't have a trailer. I use U-Haul because they are cheap. I think they come with S hooks closed on one end. Any type of shackle would get lost every time.

Any chain I have encountered will take a bolt at least the diameter of the links. Some chains are hardened and some are not.

I've never seen a U-Haul employee cross the chains. I never have either but if I did, I'd put another bolt at the intersection.