Case Hardening / Carbonitriding

Case Hardening / Carbonitriding for Machined Parts & Stampings

Case Hardening or Carbonitriding can be performed on both heavy gage stampings & low alloy machined components. It's most commonly used for plain carbon steels.

The most common case hardened depths range from 0.003" to 0.020" due to the low hardenability of the steels involved.


Although typical case depths are in the .003-.020” range, our superior capabilities and expertise enable us to reach case depths in excess of 0.100” - even for the most marginal materials.

We are also able to achieve conformance with carbonitriding requirements that other heat treaters can’t due to our ability to polymer quench after a carbonitriding cycle.  

All of our carbonitriding cycles are run in batch-type furnaces for optimum process & lot control.

Our largest furnace capable of performing the carbonitriding cycle has a working dimension of 36” x 42” x 72” and can handle weights up to 7000 pounds.

All of our furnaces are certified to the temperature accuracy and uniformity requirements of AMS 2750.

We are also able to provide selective case hardening through the application of carb stop-off paints. 

ThermTech offers carbonitriding for many steel alloys, with the following being most common:

  • 1018

  • 1117

  • 12L14

  • A-36


The process of case hardening by carbonitriding is performed by austenitizing the heat-treat load in a controlled, carbon-rich atmosphere for a length of time proportionate with the case depth requirement.

Then the part is quenched in oil to harden the developed case.


We often recommend the carbonitriding process to case harden heavy-gage stampings, low-alloy machined components, and gears.

We also offer vacuum carburizing, and vacuum carbonitriding processes with oil quenching for parts that require a different approach.

Contact ThermTech today to find out how carbonitriding / case hardening can benefit your machined parts & stampings!