Carburizing Steel

Carburizing Heat Treatment for Machined Parts & Stampings

Carburizing steel produces a hard, carbon-rich case on the outer surface of the heat treated components, while the core of the part remains relatively ductile.


As a top commercial heat treating company, we offer:

  • Carburizing 8620 Steel
  • Carburizing 4320 Steel
  • Carburizing 9310 Steel
  • Carburizing 5120 Steel
  • Carburizing 4715 Steel


All cycles for carburizing heat treatment of machined parts and stampings are run in one of our numerous batch-type furnaces. These furnaces allow for optimum process & lot control.

Our largest furnace has a working dimension of 36” W x 42” H x 72” L, and can handle up to 7,000 lbs.

All furnaces used for carburizing steel machined parts and stampings are certified to temperature accuracy & uniformity requirements of AMS 2750.

Case Depth

We run a 0.030” case depth load every night at 9pm. However, we are capable of carburizing metal to case depths in excess of 0.100” upon request.

Demanding Properties & Industries

ThermTech is a top provider of carburizing heat treatment for the Oil & Gas industry. We specialize in carburizing metal that requires mechanical and charpy impact properties.

Our superior quench and process controls enable the parts we heat treat (and not just the test pieces) to exceed the increasingly demanding property requirements of modern manufacturing.


The carburizing heat treatment process for machined parts and stampings starts with austenitizing the heat-treat load in a controlled, carbon-rich atmosphere. Components remain for a length of time proportionate to the carburized case hardening depth requirement. Then, the parts are quenched to harden the developed case.

Selective carburized case hardening is possible through the application of carb stop-off paints.

Carburize-only processes are also available, as well as blasting and straightening.


Case Harden Machined Components

In order to case harden machined components with wear surfaces, we often recommend carburizing heat treatment.

Reduce Retained Austenite Post-Quench

To reduce levels of retained austenite after quench, particularly for highly alloyed steels like 9310, we may recommend cryo-treatment after carburizing.

Steel Parts Requiring Different Properties

If you have steel products that require different properties, we may recommend gas nitriding or carburizing hardening.

Bright Finish Requirements

For bright finish requirements, we recommend vacuum carburizing with either gas or oil quenching.

Contact ThermTech to find out how case hardening can improve your products!