1333F is the carburizing, or "critical" temp for steel. From what I've read, it's above that temp that the carbon absorption and consequential hardening occurs upon quenching. That's also the temp that needs to be attained/exceeded for annealing. I could be wrong, I've also seen it listed at 900C, about 1650F. But, I think 1333F is for low carbon steel.

Last edited by Ken61; 07/27/15 08:56 AM.
I prefer wood to plastic, leather to nylon, waxed cotton to Gore-Tex, and split bamboo to graphite.