When you need a hardened surface but don’t want to break the bank…

Carbonitriding is a thermochemical diffusion process where both carbon and nitrogen are absorbed into the surface of low hardenability alloy and carbon steels to a specified depth to achieve a very high hardness or “case” on the surface of the part. The part is first heated to above the austenitizing temperature (1500 – 1650°F) in a carbon and nitrogen (via ammonia) enriched atmosphere, then subsequently oil quenched to transform the microstructure of the steel to achieve the high hardness at the surface of the part, while the core of the part remains softer.

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  • High hardness achieved on part surface while using less expensive plain carbon steels.
  • Core hardness remains softer, tougher, ductile, and impact resistant.
  • Can form a slightly harder case than carburizing (1 to 2 HRC higher).
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  • Carbonitriding depths achievable are much shallower than carburizing (0.004 – 0.020″).
  • High temperature processing can cause some distortion.
  • Generally, a grinding operation is required after carbonitriding to restore dimensional tolerances.
  • Parts can discolor or scale from oil quench and subsequent tempering operation.

Equipment Used

  • Atmosphere batch integral quench furnace.
  • Working dimensions 36″ W x 48″ L x 36″ H.
  • Weight capacity approximately 2,500 lbs.

Materials (Alloys) Treated

Low carbon steels (1008, 1010, etc.).


Stampings, high wear components, fasteners, and other high volume components.


Automotive, construction, mining, household goods.


OEMs and Tier 1 suppliers generally create their own specifications for carbonitriding.

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Need Machining as well?

Our sister company, TMD Machining, is a precision machine shop, so much so, that they specialize in aerospace solenoid valves. If you’re looking for a high quality machine shop, check out TMD.