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Gas Nitriding Heat Treatment for Machined Parts, Stampings and Tooling
ThermTech provides gas nitriding heat treatment for machined parts, stampings and tooling. Gas nitriding is an ideal heat treatment for case hardened machined components with wear surfaces. It is also ideal for parts where distortion is a concern due to tight tolerances since distortion is not typical due to the relatively low temperatures involved in the process.

Gas Nitriding Capabilities
As a top commercial heat treatment provider, we offer:

  • Gas Nitriding 4140 (pre-hardened)
  • Gas Nitriding S-7 (pre-hardened)
  • Gas Nitriding H-13 (pre-hardened)
  • Gas Nitriding P-20
  • Gas Nitriding Nitralloy 135M


Selective gas nitriding is possible through the application of nitride stop-off paints.

Batch-Type Retort Furnaces

  • All our gas nitriding cycles are run in one of our batch-type retort furnaces for optimum process and lot control.
  • All ThermTech furnaces are AMS 2750 compliant.
  • Our gas nitriding capabilities include working dimensions of 33.5” DIA X 53” long or 30” DIA x 78” long.


Case Depth

  • We run a shallow case depth load (0.003”) every week night with 24-hour turnaround.
  • We perform nitriding heat treatment for deeper case depths on a regular basis.
  • Contact ThermTech Customer Support regarding current lead-times for deeper case depths.
  • ThermTech does not provide gas nitriding services for stainless steel.


Gas Nitriding Process

  • The process of case hardening via gas nitriding is performed by heating previously hardened parts in a controlled atmosphere to a temperature below the previous tempering temperature.
  • The temperature is held for a length of time proportionate to the case depth requirement.
  • After gas nitride hardening is complete, we hand blast the parts using aluminum-oxide blast media in order to remove excess nitride stop-off paint.
  • Growth in the gas nitriding process is on the order of .0005-.001” all over due to the deposition of the white layer.


ThermTech’s Expert Recommendations for Nitride Treatment
For parts that require promotion of different properties, we recommend carburizing hardening, as well as vacuum carburizing. Both of these heat treating services reduce the need for blasting services after the hardening treatment. It is highly recommended that we perform the carburizing hardening or vacuum hardening of the rough machined component prior to nitride treatment.