We can help you determine the best Sentry furnace for your needs. Contact us with questions or to order the Model AL Pot Furnace.

Heating Element Details

In all Model AL Furnaces, the temperature is controlled by a thermocouple in the liquid bath. A dual control arrangement is recommended, and each furnace is drilled to accept a second thermocouple in the heating chamber.  The various sizes of this model each has its own unique configuration:

  • Size O - Helical wound, nickel chromium, heavy-gauge wire heating element hangs vertically on insulators on an alloy frame.
  • Sizes 1 and 2 - Sinuous wound, nickel chromium ribbon heating elements (operating on 191 Volts) hang from chamber sidewalls. Also included as standard equipment is a separately mounted, auto type transformer for direct connection to a 220 Volt, 60 Cycle, Single Phase supply.
  • Size 3 - Three separate sinuous wound ribbon elements, Y-connected for direct operation on a 220 Volt, 3-phase supply.



Electrically Heated "Workhorse" for Industrial Applications.

Model AL Furnaces are ideal for many applications. Using molten salt or lead, these small yet powerful furnaces deliver unexpectedly high rates of production. Tools and parts heat quickly in the liquid bath.

The surface protection provided by the salts and lead during the heat treatment results in consistently high quality, and selective heating of many parts can be done through partial immersion. Surface hardening treatments are easily accomplished in this high-value equipment.

Typical tool room applications within the 1650°F temperature range include stress relieving, hardening, tempering, austempering, martempering, carburizing, cyaniding and nitriding.

Among the many other possible applications for these true "workhorses":

  • Annealing of gold and copper alloys
  • Heat treatment and brazing of aluminum alloys
  • Descaling of stainless steel
  • De-enameling of porcelain enamel ware
  • Stripping plastic from plastic molding and extrusion dies
  • Melting of soft metals


  • Electric heat offers clean, safe, quiet operation and best possible working conditions
  • Uniform pot heating without hot spots
  • Carefully engineered heating elements and furnace chamber
  • High temperature uniformity and repetitive quality
  • Rapid conductive and convective heat transfer in the liquid bath
  • Ample power rating for quick temperature recovery and maximum production
  • Heavy industrial construction for trouble-free operation 
  • Long-lasting, heavyweight nickel chromium heating elements, designed for quick, simple replacement
  • High-grade insulation for maximum thermal efficiency
  • Highly insulated, lightweight, lift-off cover offers economy during idling period
  • Tapered floor and bottom drain allow easy clearance of molten salt or lead and protects heating elements from corrosion 

Model AL Pot Furnace Operating Characteristics & Specifications


Optional Equipment

To complement your Sentry furnace, we offer all types and makes of optional automatic temperature control equipment. On-off type control utilizing a magnetic contactor is suitable for most applications. Use of a current input regulator is desirable to limit the rate of melting of frozen baths and improve control at low operating temperatures. Transformers are required for connection to alternate voltage power supplies.

 Sentry Company

Sentry Company

America’s oldest steel heat treating furnace maker.