This is the first and only mention of a "6 inch diameter" in the entire thread. This forces a mental image of a round-section. Again, WTF are you talking about? First the load changes, now the shape is changing, and nobody else in this thread caught that or asked about it, so I'd caution you from accepting advice from a bunch of people that miss a critical detail like that. I've seen more engineering misinformation in this thread than I've seen in others in quite some time.
Nope, you never mentioned sheet rock anywhere, nor what you're ultimately trying to do, nor what space you're trying to do it in.
Although another person requested a photo, so I know I'm not the only one that's confused.
Are you trying to lift with the header in your garage?
You still have not said:
WHAT IS THE GOAL? Are you pulling a motor in your garage, but you don't have space? Please quote if you said what you're doing. Are you building a rotisserie? You said "weight dry/ no battery/ radiator empty" Are you picking up a car vertically, and it has no motor? WHAT ARE YOU TRYING TO DO? This could have MAJOR impacts on the answer to your question.
A piece of flat sheet steel can carry HUGE amounts of load on end without mechanical fail, no question. But the
buckling gets you every time. Context is
everything in an engineering question and the answers I'm seeing reflect that people don't understand the context.
Are you lifting your car over your motor/trans assembly? If so, are you trying to lift the whole car, or just the front? I can picture a million different things you're trying to do. Let's narrow it down to just one: The thing you're trying to do.
I've read this entire thread from end to end, twice. Don't get snarky. You asked an engineering question, I'm asking the engineering questions you
should be answering in order to get a safe recommendation to help
you out. Your ability to convey information isn't as great as
you think it is, and other people asking the same questions in this thread (that you're also not answering) bears that out.
JFC, fire up MS Paint and
draw something if you have to.
View attachment 1715847757
There, that's literally 3 minutes to draw if you don't have a camera phone. Edit: I forgot to include the sheet rock that's only mentioned once.