Arc Melt Furnace ABJ-900 is our largest system for sustained use above 3500°C with safety water flow interlock, insulated bellows, evacuation/gas system, and a heavy duty power source. The chamber hinges rearward giving complete access to the hearth area and chamber interior for easy loading, unloading, cleaning and maintenance.

The hearth plate includes many possible configurations of melting cavities and custom designs are supplied at no additional cost if specified at time of order.

The melting area is a 9.00″ (229 mm) diameter hearth cavity. Arc melting furnaces provide extremely pure melts. High vacuum turbo pumping system and other accessories available.

Arc Melt Furnace ABJ-900


General Specifications

  • Operating temperature over 3500°C (6332 F).
  • Large Bell Jar, top loading configuration.
  • 100% 304L grade stainless steel vacuum chamber.
  • Copper stinger with tungsten electrode.
  • Custom copper hearth plate 9.0” diameter (230 mm).
  • Sight window with 4″ diameter (104 mm) viewport and separate port with halogen light.
  • Power Supply: 500 Amp @ 80% Duty Cycle, 22 kVA.
  • Water-cooled with safety interlock.
  • Inert gas system with relief valve.
  • Vacuum system, rough vacuum or high vacuum.


Access to the furnace for loading and unloading is done by lifting the hinged chamber backwards, giving complete access to the loading area, hearth plate and the chamber interior. The chamber is constructed of 304L grade stainless steel and electro-polished for good vacuum integrity and appearance. The chamber is double-walled for water cooling to maintain a cool chamber temperature during operation. The chamber is vacuum rated to 10-6 Torr (mbar).

An illumination port with halogen light is provided on the side, the vacuum port for a pumping system is located on the bottom of the chamber, and a 4″ viewport with swinging eye shield is supplied for operator viewing during operation.  Clamps seal the chamber to the base and isolate the chamber atmosphere.

The copper water-cooled hearth plate has cavities to hold melt material. Custom cavity shapes are available at no charge when specified at the time of order.

Electrode stinger

The copper water-cooled  stinger  with  replaceable  tungsten  electrode provides the tip for the melting arc. A ball joint with gas pressurized bellows allows the stinger to move easily around the chamber and stay in position once released.

Inert gas system with indicating flow control, pressure gauge, and relief valve

Pumping system with roughing pump, vacuum gauge and manual valve

Vacuum System

A 2 CFM (56 LPM) vacuum pump is offered standard with a vacuum valve and a vacuum compound gauge, which allows the chamber to be evacuated to the 10-2 Torr (mbar) range. The vacuum system allows the removal of air/oxygen followed by an inert gas back-fill. This prevents oxidation of the material during heat up and melting. A diffusion or turbo pumping system is available as an option for ultra clean environments.

Gas System

A manual gas valve is supplied to quickly back-fill the chamber to a slightly positive pressure after evacuation and to keep a blanket gas flowing while arc melting. A 2 PSI relief valve will relieve excess gas while maintaining a positive pressure in the chamber. This  furnace  system  was  designed  to  operate  in  argon,  nitrogen,  or  non-flammable forming gas. The standard positive pressure for operation is .14 kg/cm sq (2 PSIG). A  30/30 compound gauge (30 PSIG x 30 in. Hg) is located on the chamber to observe chamber pressure.

Water System

A water inlet and outlet manifold distributes water to the various furnace components to keep them cool during operation. A water flow switch is provided to interrupt power in case water flow is interrupted.


Available Options for Arc Melt Furnace ABJ-900:

  • Arc casting
  • Powder melting
  • Annealing
  • Melting point determination
  • Metallic buttons
  • Creating alloys
  • Crucible welding
  • Material densification
  • High purity melts
  • Vacuum casting

ABJ-900 General Arrangement