45acp
naw man
Even though I would be using leftover steel from the scrap pile and it wouldn't cost anything, I'd still go buy wood and dump concrete in it to save the leftover steel for something else I'd probably never get around to building.Usually strength.
You make a really shitty OSB or rotten plywood box with some mesh suspended in it and the 3pt attachment points poking out of the form, pour it full and you're GTG.
The concrete comes out cheaper than the steel if you were to buy new steel and even if you don't the steel you have gets saved for more deserving projects.
I'd honestly never seen a steel box until he posted his. I just assumed everyone did concrete.