Low Carbon / General Purpose Steel

Low carbon steels contain up to roughly 0.20% carbon. That low carbon level is what makes them easy to weld, easy to bend and easy to form cold — no preheat, no special electrodes, no cracking at the weld.

What they trade away is hardness. These grades cannot be through-hardened to any useful degree, so they belong in parts where the job is to hold shape and carry moderate load, not to resist wear. Where surface hardness is needed on a low carbon part, it is added later by carburising or induction hardening.

Cold drawing changes the picture usefully: the drawing operation work-hardens the bar, lifting tensile strength and yield well above the hot rolled condition while delivering a bright surface, close diameter tolerance and straightness that a machine shop can clamp and turn without a roughing cut.