Standard vs. oversized
The platform on the top is made from 5/16ths tubing, the platform on the bottom is 3/8ths. 3/8ths tubing is noticable stiffer than 5/16ths, so if you regjularly carry depleted uranium bricks it’s probably a better bet. I find it to be considerably more massive when I’m working with it, but when it’s put side-by-side with a platform made from 5/16ths tubing it’s not obviously huger.
One thing I discovered when I bent the steel for this O/S rack (and a smaller 10x7ish one that I did for practice) is that my 3/8ths tubing bender wants to twist the end of the bend down – it’s a somewhat lighter-weight bender, so there’s a tiny bit of flex in the rotating die arm, and I think when I’m getting close to 90° I start pushing at an angle. With 5/16ths tubing, I’d just clamp the corner in a wood vise (with a couple of chunks of wood to prevent marring) and cold-set it back, but this tubing is stiff enough so it actually mars the wood before starting to bend back into line. I need to (a) replace the wood vice with a proper metal-working vise (I have one, but haven’t removed the wood vise yet) and (b) tweak the way I operate the bender so that I push towards the center of the die all the way from 0° to 90°.
This O/S rack is going to have a 5/16ths tombstone, though, because the customer wants an offset tombstone and it takes a bit of tweaking to put the bends at the bottom of the tombstone legs in the right place.