Heat Treatment

Heat treatment of steel is heating steel to a temperature, usually between 1400 and 2050 degrees F, and then cooling that steel (quenching) down quickly in order to freeze it at a structure that will remain hard. See hardenability.

Tempering is reheating to a much lower temperature (around 400 degrees+or – for two hours, two separate times to “temper” some of the hardness out, in exchange for added toughness.