For a bit of devilment I subjected a short (5") length of standard UK galvanised steel scaffold pole to the tender caresses of my newly completed hydraulic press.
No real surprise that it only took about 5 tons to effectively squash it flat, but there were still a few ripples, so I carried on to the full 60 ton to make an extremely flat tube
BUT: as the initial (5 Ton) squash was happening I was surprised to see that the tube fractured where the bend radius was smallest - obviously not a malleable steel.
Now I'd always assumed that they were made from mild steel, but this little experiment-ette would seem to give the lie to that. All google will tell me is that they must conform to EN39 specification - but that's not the steel, it's an overall size type spec as far as I can tell.
.... so what's the steel