Full Annealing

For rough gears and gear blanks, a full anneal treatment is often required before any heavy machining or forming operations can be performed. The treatment corrects any brittleness in the parts to ensure that the material is soft enough for the hobs to effectively move the material and properly form the splines and teeth.


Our full annealing treatments are run in batch-type furnaces due to their ideal process and lot control qualities. All these furnaces are certified to AMS 2750, as they conform to all of its accuracy and temperature uniformity requirements. The largest furnace we have that is capable of performing the full anneal process possesses a working dimension of 86” x 51” x 182”, and can handle parts up to 86” in diameter.


The process of full annealing gears is performed by taking the parts above the critical eutectoid temperature in the 1475F to 1650F range for a length of time commensurate with the cross section size and then slow-cooling them to promote a ferritic microstructure.  This process creates a product with maximum ductility and toughness, reduced strength and hardness, as well as improved machinability and uniform properties.


We recommend this process most often to customers whose gear products often turn out too hard or brittle as a result of their fabrication processes.
ThermTech has accumulated a great deal of experience in full annealing gears, particularly those comprised of any of the following alloys:

  • 8620 steel
  • 1018 steel
  • 9310 steel
  • 1117 steel
  • 12L14 steel

ThermTech offers several hardening processes that can be performed after a full anneal treatment. For gears sensitive to distortion but requiring hardness specs, please look into our marquench hardening process.  It is also beneficial to employ cryogenic treatments to transform retained austenite which may be present after quench for highly-alloyed gears.   These are just a small sampling of our many capabilities which enable us to meet any property and/or hardness requirements a part might have!

For a quote or more information about how our full annealing and post-annealing treatments can benefit your gear products, please contact a sales representative today!