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There’s a good reason why the heavy-duty NX Pit is the flagship of our range of nitriding/nitrocarburizing furnaces. Its innovative design incorporates multiple controlled heating zones that ensure optimal temperature uniformity inside the retort, typically +/-5 °C (9 °F) or better. NX furnaces are designed for fast heating rates and uniform temperature throughout the load.

To discuss your nitriding and nitrocarburizing furnace requirements, please fill out our “Request a Quote” form.

Model Diameter Height Load Capacity
NX-615 23½”(600 mm) 59″(1500 mm)

2200 lb. (1000 kg)
NX-620 23½”(600 mm) 78¾”(2000 mm) 2600 lb. (1200 kg)
NX-815 31½”(800 mm) 59″(1500 mm) 3300 lb. (1500 kg)
NX-820 31½”(800 mm) 78¾”(2000 mm) 3850 lb. (1750 kg)
NX-825 31½”(800 mm) 98½”(2500 mm) 4400 lb. (2000 kg)
NX-1015 39″(1000 mm) 59″(1500 mm) 4400 lbs (2000 kg)
NX-1020 39″(1000 mm) 78¾”(2000 mm) 5500 lb. (2500 kg)
NX-1025 39″(1000 mm) 98½”(2500 mm) 6600 lb. (3000 kg)
NX-1215 47¼”(1200 mm) 59″(1500 mm) 6600 lb. (3000 kg)
NX-1220 47¼”(1200 mm) 78¾”(2000 mm) 8400 lb. (3800 kg)
NX-1225 47¼”(1200 mm) 98½”(2500 mm) 9900 lb. (4500 kg)
NX-1230 47¼”(1200 mm) 118″(3000 mm) 11570 lb. (5250 kg)
NX-1625 61″(1550 mm) 98½”(2500 mm) 13200 lb. (6000 kg)
NX-1630 61″(1550 mm) 118″(3000 mm) 15400 lb. (7000 kg)
NX-1635 61″(1550 mm) 137¾”(3500 mm) 17600 lb. (8000 kg)
NX-1645 61″(1550 mm) 177″(4500 mm) 22000 lb. (10000 kg)

NOTE: Nitrex reserves the right to make changes without notice.
For non-standard sizes, please contact Nitrex

  • Inconel 600 (refractory steel) retort and racking for long service life and non-reactive interaction with nitriding atmosphere
  • Uniform temperature distribution obtained through independently controlled heating zones and intensive atmosphere circulation ensuring full control of nitriding potential throughout all stages of the process
  • Light ceramic fiber insulation reduces heat loss and thus energy consumption
  • Kanthal long-lasting heating elements
  • Integrated cooling systems
  • Larger furnaces may be equipped with a ‘Turbo’ cooler for accelerated load cooling. This option is used where productivity is a major issue.
  • Preconfigured and factory tested
  • Pretested for metallurgical results
  • Fully automated operation guarantees repeatable and consistent results
  • True Nitriding/Nitrocarburizing Process Control – Compliant with AMS 2759/10 and AMS 2759/12 standards
  • Superior case properties per customer specifications
  • Various case configurations possible
  • Repetition of results
  • System for data archiving and reporting as well as remote diagnostics
  • SCADA connectivity
  • Clean, environmentally-friendly processes powered by Nitrex effluent neutralizers


The Nitrex process control system is a product of extensive R&D in process automation and enables accurate process execution and consistent results. The entire nitriding/nitrocarburizing process is automatic, self-adjusting and operator-independent.


This expert system monitors and responds to changes in nitriding conditions by regulating the following parameters and operating functions:

  • Furnace heating functions such as process temperature, and overheat control with automatic emergency procedures
  • Atmosphere composition and cycle flow
  • Nitriding atmosphere ratios
  • Nitriding Potential KN (dissociation rate, for customer defined cycles)
  • Temperature for each process stage
  • Gas pressure inside the retort
  • Gas recirculation
  • Execution of the cooling stage and shutdown
  • Cooling water
  • Process safety features



With our “set and forget” process, the user selects the desired recipe from a library of researched and tested recipes and initiates a process. From there, all stages of the nitriding cycle (e.g., purge, heat, process control, cool) are automatically sequenced in one uninterrupted cycle, without further operator intervention. This setup provides a high degree of accuracy in process execution, contributing to consistent nitriding/nitrocarburizing results.