Belt Grinder 2x72" and 50x2000 mm

[toomast]

There is a way to treat low carb steel / mild steel/ . You heat it at 315C, keep it there a couple of minutes, thin oxide layer forms in black, then you brush it with some oil and it goes even blacker. Result is much tougher part, even if not a high carbon steel. Black oxide layer is not real anti rust though it gives some protection


bellow you could compare bare cold drawn steel bar and treated.

Interesting. What is the "official" name of this process?