Cryogenic Heat Treatment

Deep Freeze Heat Treatment for Tool & Die Applications

Highly alloyed tool steels have a tendency to form potentially deleterious retained austenite after hardening. For this reason, Cryogenic Heat Treatment is used to transform this retained austenite into martensite. This Deep Freeze Heat Treatment is also used to promote dimensional stability prior to sensitive machining and grinding operations, especially for certain aluminum components. Cryo Heat Treating also serves as a stress relief operation.


The majority of our Cryogenic Heat Treatment cycles are ran in one of our liquid nitrogen cryo-boxes for optimum process and lot control. Our largest cryo-box has a working dimension of 33” x 47” x 47”.

We also have the capability to cryogenically treat larger parts on demand.


Therm Tech uses liquid nitrogen as the cooling medium in our cryo boxes. The material is taken down to the process-specific freezing temperature and held at the deep freezing temperature for an extended period of time. The cycle times and temperatures may vary depending on the part and the application; however most parts are taken to -120F to -320F. The lead time for this process is usually a day or so.


We often recommend Cryogenic Heat Treatment for parts when retained austenite is an existent or potential issue.

We are capable of Nitriding at temperatures down to -120F or even -320F. Typical lead-times for these treatments are typically 1-2 days, but can be run overnight in cases of emergency.

Cryo heat treating may also be used on occasion to gain an additional Rockwell “C” point of hardness after hardening. In cases where your part isn’t quite hard enough, adding a cryo heat treating operation can make the difference!

Cryogenic Heat Treatment is also used as an important part of shrink fitting operations.

Shrink Fitting is a process in which two parts are permanently stuck together by capitalizing on the thermal expansion properties of steel.

Shrink Fits are sometimes preferential to welding operations because shrink fitting does not necessarily involve any loss of properties or high temperatures.

Depending on individual product needs, we also offer Thermal-Cycling along with processes, including but not limited to Vacuum Hardening and Oil Quench and Temper, in order to meet any hardness or additional property requirements.

Contact us to discuss cryogenic heat treatment or send files for a quote.