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Heat Treating for Gear Manufacturing

Furnace Solutions That Meet Your Requirements

mesh belt conveyor furnace

Material science and thermodynamics are applied in heat treating to achieve mechanical performance in gears. The technique includes part design, fixturing, and process development. The challenge is to understand which furnace type can most effectively process the gear design and material grade. Surface offers furnaces for all steps in gear manufacturing from forge pre-heat furnaces to normalize and anneal of gear blanks. Protective-atmosphere furnace solutions are well-suited for hardening of gears. The process techniques include gas or vacuum carburizing, carbonitriding, and neutral hardening in a carbon-based atmosphere or in a vacuum.

For over 100 years, Surface® Combustion has provided thermal processing equipment for gear manufacturing.

We build the most rugged, reliable equipment for gear heat treating. Surface serves the various industries who benefit from gear components and has practical knowledge of the specifications that must be met. Surface equipment for gear processing matches the durable, dependable strength defined by your application. Our aftermarket services support maximum uptime for your operation.

Surface Combustion Suggested Furnace Types

The batch integral quench (BIQ) furnace design enables oil quenching under controlled atmospheres. Vacuum carburizing furnaces are a more recent development can be coupled with gas and/or oil quenching. Hybrid batch integral quench furnaces have a controlled atmosphere hot zone coupled with a vacuum-purged quench vestibule. Hybrid designs offer energy savings and better work environments.

VacuDraw tempering furnace & Allcase batch integral quench furnace

Our Products

Surface offers multiple batch and continuous solutions for through hardening, carburizing, or carbonitriding for gears.

  • Allcase® BIQ Furnace
  • Belt Furnaces
  • Pusher Tray Furnace
  • Roller Hearth Furnace
  • RTB™ Single Chamber Atmosphere Box Furnace

Gear Types

The many gear types processed by Surface equipment include:

  • Bevel Gears
  • Helical Gears
  • Internal Gears
  • Miter Gears
  • Rack and Pinion
  • Screw Gears
  • Worm and Worm Gear

Gear Metals

The metal selected for the gear, as well as the processing, depends on the application needs. Gears are typically made from:

  • Steel
  • Alloy steel
  • Mild Carbon Steel

Treatment Options and Considerations

Part Specifications

Surface furnace solutions for heat treating help ensure the performance
of gears to meet application needs and performance specifications.

  • Low Distortion
  • Tooth Hardness
  • Case Depth Control
  • Life Cycle Optimization

Process and Capacity Variables

Processes available for gear heat treatment are well established and controllable with atmosphere carburizing, while vacuum carburizing is modeled on a case by case since it is empirical. The technologies that have improved distortion are high pressure gas quenching, but better material grades are required, both add costs. Other advances are better insulation and heating technologies, improved process control sensors and better quench modeling/design. As such, the temperature uniformity, carburizing or nitriding potential uniformity and quenching are significantly better than in the past.

Comparing BIQ rated capacity today to continuous pusher furnaces shows batch loads are highly productive. Today it is advisable to invest in the flexibility of up to three BIQ furnaces before considering continuous pusher type furnaces.

Process Considerations

  • Load mass and volume
  • Part geometry
  • Material alloy and hardenability
  • Uniform case structure (root to pitch)
  • Distortion control

Equipment Considerations

  • Operating costs
  • Maintenance costs
  • Capacity
  • Floor space requirements
  • Infrastructure requirements

Ready to Get Started?

Please call us when you are ready to discuss a new furnace or maintain, upgrade or replace your furnace or any part of your furnace. At Surface, we look forward to helping you with any thermal processing needs.

Call Surface with the following information ready to initiate your furnace solution.

  • furnace cyclecycle
  • furnace operationoperation
  • hours per yearhours per year
  • available spaceavailable space
  • operating temperature rangeoperating temperature range
  • heat sourceheat source

Give Us a Call

(800) 537-8980