Screw heat treatment, we also call the screw hard. The screws are divided into iron and stainless steel screws. Iron is generally harder if it needs to be harder. All need to be hardened. But stainless steel screws rarely need to be hardened. Because its hardness is enough, it is hard enough. The iron heat treatment method for iron is described below.
First, the heat treatment method: different heat treatment methods can be selected according to the object and purpose.
Quenched and tempered steel: high temperature tempering after quenching (500-650 ° C)
Spring steel: medium temperature temper after quenching (420-520 °C)
Carburized steel: quenching after carburizing and then low temperature tempering (150-250 ° C)