Cyclone Gas-Fired Retort Pit Nitriding Furnace

Cyclone Gas-Fired Retort Pit Furnace

Gas-fired pit furnaces with built-in retort available in single or two-stage nitriding systems. Cyclone gas-fired top loading furnaces are capable of temperatures up to 1250°F (1400°F optional). The furnaces have a separate heating/fan chamber that provides heat to the work chamber. The work chamber is heated when the supply gas is burned in the heating chamber then pressurized by a rapidly circulating fan. Pressure above, and suction below, force the heated gases through and around the retort at high velocity with minimal temperature drop. Excess volume is forced out through a flue after passing through the work chamber. A "suspended" fan shroud mates with either the basket or baffle to provide a closed path of circulation when the cover is closed. Atmosphere leaves the fan and travels downward through annular clearance between retort and basket or shroud to below the load support, then upward through the work before again entering the fan inlet. 


  • Exceptionally high surface hardness
  • Parts with high resistance to metal-to-metal wear
  • Lower finishing costs—minimizes warpage, distortion, galling, and seizing
  • Improved corrosion resistance—especially if parts are not subjected to a final finishing operation after nitriding


  • Exceptional uniformity
  • Long service life
  • Fast, efficient cooling
  • Simplified installation
  • Fast, efficient cooling
  • Nominal maintenance


  • Ammonia dissociators
  • Removable retort for accelerated cooling
  • Automated and programmable systems


  • Nitriding