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What You Need to Know When Purchasing Conventional Heat Treat

Advanced Heat Treat Corp. (AHT) offers several conventional heat treatments in Waterloo, Iowa. AHT also offers induction hardening at its Cullman, Alabama location. Learn about purchasing quench & temper, carbonitriding, carburizing and induction hardening below.

posted On Tuesday, August 9, 2022 in Blog

Below we discuss carbonitriding, carburizing, quench & temper and induction hardening. We also discuss details when filling out purchase orders, how to minimize costs and more.

Use the buttons below to jump to the most frequently asked purchasing questions or scroll down to view the full blog:

What to include on your Purchase order How to reduce costs SHIPPING ADDRESS size capabilities


What is Carburizing?

Carburizing is a surface or case hardening process normally applied to low-carbon steels. During processing, carbon is diffused into the surface of the parts at elevated temperatures. Hardening occurs to this “carburized case” by quenching in oil from above the transformation range, resulting in a hard surface for wear resistance and soft core for ductility.

What are the benefits of Carburizing?

  • Hard surface with high wear resistance
  • Deep case depth potential
  • Improves durability

What materials are best-suited for Carburizing?

Low Carbon Steels (ex: 1018, 1117) & Low Carbon Alloy Steels (ex: 4120, 4820, 8620, 9310, etc.)


What is Carbonitriding?

Carbonitriding is a modified form of gas carburizing in which ammonia is added to the carburizing atmosphere. Thus, both carbon and the nitrogen from the ammonia are diffused into the steel simultaneously. The diffusion of carbon results in a high carbon surface while the nitrogen increases hardenability, supporting a potential increase in hardness. Carbonitriding produces a shallower case and is well suited for plain, low-carbon steels.

What are the benefits of Carbonitriding?

  • Improves fatigue resistance
  • High surface hardness and tough core with low cost material
  • Improves wear resistance

What materials are best-suited for Carbonitriding?

Low Carbon Steels (Ex: 1008, 1010, 1018, 1117, 12L14)

Quench & Temper

What is Quench & Temper?

The quench and temper process, also known as "through hardening", consists of heating the parts to a temperature above the transformation range and rapid cooling to room temperature, usually using an oil quench. This may be performed in air or in a controlled atmosphere to protect the part's surface. Parts are then reheated to a lower temperature to temper to the desired final hardness range.

What are the benefits of Quench & Temper?

  • Improves strength and hardness
  • Controllable specific mechanical properties
  • Increases lifespan of part
  • Relatively short cycle/cost effective

What materials are best-suited for Quench & Temper?

Medium Carbon, High Carbon Steels, Medium Carbon Alloy Steels and Cast Iron

Induction Hardening

What is Induction Hardening? 

Induction Hardening is a form of heat treatment in which a steel or cast iron part is heated by electromagnetic induction, immediately followed by rapid cooling (quenching). Upon quenching, the metal undergoes martensitic transformation, significantly increasing its hardness. It is a selective heat treatment, only heating the area that needs hardening.

What are the benefits of Induction Hardening?

  • Increased surface hardness, strength and wear resistance
  • Deep case with tough core
  • Parts may be tempered after induction hardening to adjust hardness level as desired
  • Selective hardening process with no masking required
  • Relatively minimal distortion
  • Allows use of low cost steels such as 1045
  • Frequently the most economical treatment method per pound

What materials are best-suited for Induction Hardening?

Alloy steels, carbon steels, cast irons, tool steels, certain 400 series stainless steels. 1045 is the most popular steel for induction hardening, closely followed by 4140.

RELATED CONTENT: Induction Hardening: The Pros & Cons

Tips for Purchasing Conventional Heat Treat 

What should I include on a Request for Quote (RFQ) for Conventional Heat Treat?

  • Print if available
  • If the print or project description does not include a part number, please assign one (should match what would be listed on a PO)
  • Typical lot size and EAU
  • Material if varying from print
  • If not included on print:
    • Surface hardness and case depth (should be minimums or reasonable ranges - not single numbers)
    • Location of the minimum zone to induction harden, any areas which must be kept soft and remainder considered optional (Induction Hardening only)
  • Certification requirements

What should I include on my Conventional Heat Treat Purchase Order (PO)?

  • Part number
  • Quantity
  • AHT quote number if project has been quoted
  • Print revision if AHT has on file from quoting, or include print as available
  • Material (not required if it matches print and print only lists one choice)
  • Process required and specifications (not required if a quote is referenced)
  • Any specifications which are not covered by or deviate from the print
  • Special shipping instructions, if applicable, otherwise default is to return to customer using same method as incoming
  • Rust preventative requirements, if any

See a more detailed blog about purchase orders here.

What can I do to reduce my costs when I buy conventional heat treat services?

  • Involve AHT early in the process if the project is not established
  • Include all necessary information on purchase orders (see above)
  • Increase lot sizes
  • Don’t over-spec case depth
  • Allow minimums or generous ranges on case depth and surface hardness

What quality certifications does AHT hold?

Advanced Heat Treat Corp. holds certifications such as Nadcap, AQS (aerospace quality system), ISO, IATF, FFL (Federal Firearms License) and we are ITAR registered and CQI-9 compliant. Learn more and view all these certifications at https://www.ahtcorp.com/quality/

Where are Advanced Heat Treat Corp.'s conventional heat treat services offered?

2839 Burton Ave., Waterloo, Iowa 50703

Induction Hardening is also offered at 1545 County Road 222, Cullman, AL 35057.

What are AHT's size capabilities for conventional heat treat? 

  • Induction Hardening: Up to 61" is possible, but if the part needs hardened end-to-end 54" is the maximum length. 800 lbs maximum weight.
  • Carburizing & Carbonitriding Furnaces: Up to 48" length, 36" width, 36" height and 3,000 lbs. weight
  • Temper/Draw Furnaces: Up to 96" length, 108" width, 52" height

Aside from the heat treatments listed above, what other heat treat services are offered at AHT?

Our Burton Ave. location in Iowa offers age/precipitation hardening, annealing (sub-critical), cold treatment, normalizing, stress relieving, magnetic particle inspection (MPI), failure analysis and more. 


Our Cullman, Alabama; Monroe, Michigan and MidPort Blvd. location in Iowa provide nitriding services such as ion nitriding, gas nitriding and ferritic nitrocarburizing. It also offers additional services such as UltraOx (FNC+black oxide with a proprietary sealant), metallurgical consultation & more. 


Have additional questions? Please contact us at 319-232-5221 or fill out our Contact Form

This article was originally written in January 2020, but was updated on 8/9/22 when the AHT location in Cullman, Alabama added Induction Hardening to their list of services.

  1. burton
  2. carbonitriding
  3. carburizing
  4. induction hardening
  5. quench and temper