Benefits and Process of Blast Cleaning After Heat-treatment

After the heat treatment of metal and steel components, it’s common to see the formation of an oxide layer or scale. Blast cleaning, specifically shot and grit blasting, is employed to combat these undesired formations and enhance the overall quality of the finished parts. Let’s explore the process, its benefits, and important considerations:

Blast Cleaning Process:

Heat treating operations, particularly on forgings, gears, weldments, tooling, castings, and machined components, can lead to oxidation depending on the specific process parameters. The primary purpose of blasting after heat treatment is to remove this oxidation or scale that forms during these procedures.


  • Oxidation Removal: Blasting effectively eliminates the surface oxidation that can form during thermal operations. This not only ensures a cleaner surface but also makes subsequent operations like lot number stamping and machining much more straightforward.

Technical Benefits:

  • Surface Cleaning:
  • Efficient Oxide Layer Removal: Unwanted layers that form during heat treatment, like oxide scales, are effectively removed, unveiling a clean metal surface beneath.
  • Elimination of Impurities: The process also aids in the removal of contaminants such as dirt, oil, or grease.
  • Surface Profile Enhancement:
  • Improved Adhesion: Blasting creates a rough surface profile, promoting enhanced adhesion for coatings, paints, and sealants, ensuring longevity and reduced maintenance.
  • Uniform Surface Finish: It ensures a consistent and even surface finish, critical for the aesthetic aspect of steel components.
  • Enhancing Fatigue Life:
  • Micro-Hardness Boost: The blasting process can slightly harden the surface, offering increased resistance to wear.
  • Surface Homogeneity: By eradicating surface imperfections, it reduces potential initiation sites for fatigue cracks.
  • Preparation for Further Processing:
  • Optimization for NDT: Clean surfaces are paramount for non-destructive testing methods.
  • Enhanced Welding: Purified steel surfaces lead to stronger, defect-free welds.

Recommendations and Special Considerations:

At ThermTech, we offer diverse blasting options tailored to specific needs:

  • For processing forgings or castings, we use a 36 cubic foot tumble blast.
  • For larger parts, we have a 72” diameter table.
  • In cases with especially fragile parts, ThermTech provides rubber belt tumble blasting or hand blasting capabilities using finer blast media.

 However, it’s crucial to note that blasting steel products creates an active surface on the part, enhancing the propensity for a thin rust layer, especially under humid conditions. If this is not desired, we highly recommend inquiring about our post-blast rust inhibiting.


Blast cleaning post heat-treatment is more than an aesthetic choice. It introduces manifold technical advantages, ensuring steel parts that not only look better but also function optimally and have an extended lifespan. With ThermTech’s advanced facilities, your components are guaranteed top-tier treatment and results.

ThermTech—Experts in Austempering Stampings, Machined Parts, and Investment Castings

ThermTech, Inc. offers both small and large batch capabilities for austempering steel and iron investment castings. Between our neutral salt bath furnaces and our larger austempering furnaces, we have the capabilities to austemper a wide variety of stamping, machined components, and investment castings. We have run austempering on alloys from 1060 through 4340 to ductile iron machined parts.

Our dedicated team works with you to ensure we meet your specifications. Count on our decades of experience with hardening, tempering, surface heat treatments, vacuum treatments, and annealing. To learn more about our services, please contact us today.

Learn more about austempering and how ThermTech can serve you by watching these videos.

Request a free quote online or call us at 800-752-6917. You can also contact us online for all your austempering and heat treating needs.


    ThermTech’s quality policy is ZERO DEFECTS for all customer products and in all quality management system activities. Through our efforts to continually improve the quality of the work we offer, we’ve been recognized as being able to meet the rigorous quality standards required by several of our major customers. ThermTech is certified for ISO 9001 and AS9100 in both Metal Heat Treat and Metal Finishing.