Definition - What does Through Hardening mean?
Through hardening is a process used to improve the hardness and tensile strength of a metal alloy. This process involves using a rapid quench technique to change the microstructure of the metal while imparting increased strength. In contrast to case hardening, which strengthens only the outer layer of the material, through hardening strengthens the entire cross-section of the alloy.
Corrosionpedia explains Through Hardening
The depth to which a steel alloy will harden depends on the rate of quenching. For instance, faster quenches with brine or water will produce a deeper hardening effect than cooling the alloy with oil or air. While through hardening increases the material’s strength and hardness, through-hardened components are relatively brittle compared to those that are quenched normally.
Through hardened components are ideal for situations where hardness, strength and wear resistance are paramount. Some applications that regularly use through-hardened materials include:
- Hand tools
- Springs, axles, blades and bearings
- Parts that are subjected to significant loading, such as nuts, bolts, brackets and chains
- Some automobile components