Why do screws need to be hardened?
The so-called hardening of screws refers to the hardening of screws required by customers, which is also known as heat treatment. Need to stiffen means to heat treatment of screws.
Hardening of screws is also called quenching, quenching can increase the hardness, but the screws need toughness, need high tensile strength, do not need high hardness. Therefore, general screws need to do quenching + high temperature tempering, also known as tempering treatment, in order to enhance the tensile strength of the screw, simple understanding is to harden the screw, add the hardness of the screw itself.
Why harden the screws? Mainly because a lot of screws if not used before hardening, it is easy to slip teeth or break the head, so increase the link of hardening screws, hardening screws to solve the problem of screw sliding teeth, screw broken this phenomenon.
Generally speaking, only iron screws need to be hardened stainless steel screws are rarely hardened. And the high strength of the screw itself wire is hardened, hardness is relatively high, but some still need to be hardened to achieve high strength of this grade.