Single Chamber Vacuum Furnaces

Based from more than 40 years of experience in the vacuum furnace manufacturing industry, ALD-Holcroft brings to the NAFTA region the MonoTherm® line of single chamber vacuum furnaces. This furnace type is centered on continuous improvements to the equipment and process technology and yields highly reproducible results with excellent efficiency.

Flexibility Pays Off

The MonoTherm vacuum furnace has broad capabilities and can be used in a wide variety of heat treatment processes including:
  • Annealing
  • hardening
  • tempering
  • brazing in fine respectively high vacuum
  • case hardening
  • sintering
With the modular design principle, enabling different workload sizes in rectangular and cylindrical shape hot zones, every size model can be adjusted to meet your specific needs. MonoTherm vacuum furnaces are widely used by commercial heat treaters to provide vacuum processes. The increased flexibility in design enables its use in production facilities as well as universities and research departments. With such wide appeal and versatility, the MonoTherm can be found in the aviation and aerospace industries, automotive segment, tooling manufacturers and even producers of magnets. The ALD-Holcroft MonoTherm furnace is truly unique.

Vacuum Heat Treatment

In vacuum heat treatment, the exclusion of oxygen prevents oxidation of harmful components, which occur in other types of traditional atmosphere furnaces. This method of vacuum processing is especially useful for the treatment of high and medium alloyed steels, as well as for brazing and sintering. The heating can be convective or in vacuum. For quenching, inert gases are being used and available in pressures from 2 to 20 bar. Optionally, the furnace can be modified for other processes, such as low pressure vacuum carburizing (LPC).


The concept of the MonoTherm vacuum furnace offers all options to create a versatile heat treatment system, adjusted to the requirements of the user. The advantages are:
  • Highest product quality
  • reduced production cost
  • increased efficiency
  • improved productivity
  • very low environmental impact


Product Literature Currently Available


• Convection heating for faster, uniform heat-up to 1500°F (800°C)
• Quench gas flow choices (top/bottom, bottom/top or 360°) 
• Quench fan speed control; low-distortion dynamic quenching
• Subzero, cryogenic cooling system to transform residual austenite
• Partial pressure control to prevent sublimation of alloying materials.

Additionally, individually controlled heating elements on the front door and rear wall are also available for temperature uniformity needs of +/-5°F (+/-3°C).

The MonoTherm can be configured with graphite heating elements and graphite insulation as well as all metallic heating elements with metallic radiation shield type insulation.