Got a random side project today, so I focused on that. I'm not entirely sure what it is, but he said it is going to get some weight stacked on it, and get pulled against. Said something about a treadmill as well. Its kinda beefy for a workout machine if you ask me, but I think it turned out nice. Everything is 3/8" wall, so its heavy.
Those are the smallest D-rings I could find.