Got a frictional wear or corrosion prevention application?

Ferritic nitrocarburizing, or FNC for short, is a thermochemical process where nitrogen (via ammonia) and carbon react with the iron content at the surface of alloy and carbon steels to create a shallow (microns), very high hardness “compound” layer. The part is heated to a general temperature range between 1000 – 1075°F in a nitrogen and carbon enriched atmosphere to form a hard “shell” on the surface of the part, and a very shallow diffusion zone beneath this layer.

Additionally, an oxide layer can be added at the surface of FNC parts which will further inhibit corrosion. The oxide layer appears as a dark gray matte finish on the parts that turns black when oiled. This process can stand up to rigorous salt spray requirements and can be an effective replacement for environmentally unfriendly chrome plating.

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  • Excellent process for parts that will experience frictional wear in application.
  • High surface hardness, low dimensional movement process.
  • Compound layer offers some residual corrosion resistance.
  • An oxide layer can be added post-FNC that greatly improves the corrosion resistance and also gives the part an aesthetically pleasing dark gray/black appearance.
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  • Depth of hardness is very shallow (microns).
  • Compound layer can be porous, which is not ideal for all applications.

Equipment Used

  • Sealed retort positive pressure furnace.
  • Working dimensions 42″ diameter x 68″ height.
  • Weight capacity up to 10,000 lbs.

Materials (Alloys) Treated

  • All carbon and alloy steels.
  • Stainless steels by special process (DMT furnace will be capable soon).


Any part that will experience frictional wear or would benefit from corrosion resistance. The FNC + oxide process has been proven an effective and more environmentally friendly replacement to chrome plating.


Automotive, aerospace, defense, firearms and others.


  • AMS2759/12 & AMS2759/13 (DMT’s furnace is not yet qualified for these specs).
  • OEMs and Tier 1 suppliers generally create their own specifications for FNC.

Contact DMT to Learn What We Can Do For You

At Darby Metal Treating we are happy to help. Give us a call or send us a message by using one of the buttons below!

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.