Series HS3 GT - High Speed Steel Inert Atmosphere GT Box Furnaces

HS3 GT Series box furnaces for hardening and pre-heating high speed steels or firing ceramics under inert atmosphere to 2450°F. GT models are designed with a continuously welded furnace shell, gasketed door assembly, and atmosphere inlet and outlet ports for operation with a positive flow of atmosphere. These models are best suited for constant operation to maintain a dry refractory environment in the work area to minimize oxidation on workloads.

The control package includes an SCR power supply which proportions the lowest power input required for each application, limiting amperage. Combined with silicon carbide heating elements designed with a 200% aging factor, this unique operating system saves money by providing excellent element life. In addition, initial purchase cost is lowered by eliminating the large expensive power transformer and oversized contactors. Operation is simplified without the manual adjustment of tap switches. Constructed with heating elements mounted above and below the hearth and lined with ceramic fiber insulation for fast uniform heat. This energy efficient furnace promotes reduced power demand, quicker recovery rates, and lower utility costs.

All models are completely wired, assembled, test fired and shipped ready for connection to 230 voltage and atmosphere supply. Compact design, fast installation, and simple, safe, dependable operation. Available in five standard models sizes.

Standard Features

  • Continuously welded sheet metal shell construction with structural reinforcement.
  • Silicon carbide elements mounted above and below the hearth for uniform heat.
  • SCR power supply.
  • Multi-layered 6" of energy efficient ceramic fiber and mineral wool block insulation for maximum heat storage, reduced heat loss and lower utility costs.
  • Silicon carbide hearth plates support the work load and readily transfer heat from the floor elements.
  • Double-Pivot horizontal swing door with gasket seals against furnace faceplate.
  • Safety micro-switch shuts off power to elements when door opens.
  • Honeywell digital temperature controller with type R thermocouple.
  • Controls are mounted below furnace in an enclosed cabinet and operate on 230 volts.

Recent News

  • Lucifer Furnaces equips ETREMA Products with HS3-GT Furnace


Flow meters, regulators, oxygen analyzers, dew point indicators, program controllers, over temperature safety systems, timers, recorders, quench tanks, computer interface, gloves and tongs.


Model Chamber Overall KW Voltage Weight (lbs)
H" W" L" H" W" L"
HS3GT-K12 12 12 12 66 41 27 8.6 230/1 585
HS3GT-K18 12 12 18 66 41 33 11.8 230/1 670
HS3GT-K24 12 12 24 66 41 39 15.5 230/3 755
HS3GT-M18 12 18 18 66 47 33 16.6 230/3 770
HS3GT-M24 12 18 24 66 47 39 18.5 230/3 865