If (IF- It's a big IF....) one were to take the 1211 out of there as maybe being what got heat treated... (Not disagreeing, I think that's a heat treating mark, not a product designation)... Well, IF..... 1211 is a mild steel that work hardens pretty OK and cuts well. Screw machine stock. Bought in rods, pulled through dies (or bought already drawn through dies), and well, old timey screw machines liked it. You couldn't "heat treat" that per se, but carburizing it is common. Crispy on the outside, chewey in the middle.
That said.... That extrapolation is WAY out on a limb, but if that were my hooch of bargain metal, I'd use that not as a guess as to what it is, but as a guide for how to start and what to look for first. I'd hack saw off an inch piece of one end of those (Ends get hot, you've got to go in a little deep to get past "surface hardening" or "case hardening" on the end of a rod). and set after it with the files, scribes, punches, a ball peen hammer etc, whatever else you might think of, and see what I could deduce.
If it's case hardened (including but not limited to carburizing), you'll know it.
If it's through hardened, you'll know it.
If it's a chrome steel, you'll know it.
If it's not hardened at all, you'll know it.
Then when you're done with the files and punches, you can take that hack sawed inch piece, put it on an anvil or the back of a vise and wail the crap out of it with a ball peen hammer. The "round side", the exposed "end of the bar" side, and the fresh cut side. You can categorize that as broadly as the "Under 50 ksi class stuff, or the over 70 ksi class stuff just by comparison to known material.
Then take the long piece you've cut the "slug" off from, put it in the lathe. With a center if you need to. Take the first three, four, five inches (whatever....) and turn it down to half, seven sixteenths, or three eighths of an inch. Whatever you feel comfortable to bend in a vise. Put the bar in a vise, put a pipe about half way over the turned down section, about half way over it. Whatch how it bends- Bends sharp, bends to an arch, bends all at the point where the turned down section meets the parent stock. What way does it bend? Does it bend progressively and continuously, or does the effort required drop off quickly? And (the reason I picked fractional dimensions), how does that compare to a grade 8 bolt, a grade 5 bolt, or an unmarked bolt?
You might never know exactly what it is, but that'll all give you some idea of how much you want to rely on it in structural ways. (Soft, hard, brittle, maleable, work harden, what finish can you get out of it... All the good stuff.
And no, you don't "have" to use a hack saw, but if you're paying atteention to it, that's another good "gut feel analysis" tool...
