ASTM B117 is a salt spray test used to produce relative corrosion resistance information for specimens of metals and coated metals exposed in a standardized corrosive environment. Micom offers ASTM B117 accelerated corrosion testing as part of its surface finish and accelerated aging testing services.

ASTM B117 uses and factors to consider

According to ASTM International, ASTM B117, in and of itself, is not a test specification. Rather, it outlines the standard practice for operating salt spray (fog) apparatus. B117 is a document establishing the parameters and requirements for operating a salt spray test chamber. It specifies how to create and maintain the salt fog test environment so that results can be achieved consistently from lab to lab and chamber to chamber.

ASTM B117 does not specify anything about the type of test specimen, dimensions, shape or exposure periods to be used for a specific product, nor does it have any requirements or guidance for the interpretation of the results.

ASTM B117 is used in many industries, including:

  • Automotive (example: SAE J14563, GM 4298P…)
  • Paints and Coatings
  • Aerospace
  • Military (MIL-STD-810)

Among others, the following test methods call up practice ASTM B117:

ASTM D1654M0140 (Nissan)
ASTM D1735SAE 1455
ASTM D2247GM 4298P (General Motors)
ASTM D5894GM 9540 (General Motors)
ASTM G44TSH1552G (Toyota)
ASTM G85HES 6501 (Honda)
ISO 9227SAE USCAR – 24
MIL – STD – 810 meth. 509.4
MIL – STD – 331B


This practice is used in many other standards, both in North America and across the world.  For a list of salt spray tests please see: salt spray methods list.

The type and number of test specimens to be used, as well as the criteria for the evaluation of the test results, will be required in the specifications covering the product being exposed or shall be mutually agreed upon by the parties involved.

Reasons for ASTM B117 Testing and Results

There are many different reasons for which you should conduct salt fog testing, chief among them is determining the effect of corrosion on your specimen. Different metals and surfaces can exhibit differing amounts of resistance with respect to corrosion, and ASTM B117 testing will allow you to compare this. It will also allow you to judge a surface’s tendency to corrode when it is scratched as well as the adhesion of its coating.

The results you gain from salt spray testing will allow you to gauge how well your metal, surface or coating can resist corrosion. By combining ASTM B117 with some of the other tests mentioned above, like ASTM D1654 and ASTM D3359, you can also see how much scratching will affect the corrosion of your specimen and how far corrosion creeps.

Typical Experimental Parameters for the ASTM B117 Test

There are numerous parameters we will want to confirm with you in order to run a proper ASTM B117 salt spray test. These include:

  • Number of specimens/products: usually 1 (to be confirmed)
  • Specimen dimensions: 3” X 6” (Typical for flat specimen. 3D samples can also be tested. Please specify dimensions)
  • Exposure duration: hours
  • Optional sample preparation to be specified:
    • Cleaning
    • Scribing (ASTM D1654 or other)
    • Edges protection if exposed
  • Orientation (if required please specify): While in the salt spray cabinet, specimens shall be supported or suspended between 15 and 30 degrees from perfectly vertical and, preferably, parallel to the principal direction of flow of fog through the chamber, based upon the dominant surface being tested. Samples shall be supported by their bottom or side.
  • Visual inspection (if specified please specify time intervals)
  • Post-test evaluations:
    • You may require interval/post-test evaluations for your sample(s).

The following test methods are most often requested

  • ASTM D610: Rusting on painted metal
  • ASTM D714: Blistering on painted metal
  • ASTM D1654: Rust creepage (final inspection)
  • ASTM D3359: Tape Adhesion
  • ASTM D3363: Coating Hardness
  • And many others…

Corrosion Tesiting Equipment


Other related test methods

As mentioned above, ASTM B117 is a specific accelerated aging test.  For other aging tests and additional test methods related to ASTM B117, please see UV testingClimatic chamber testing, Coating testing.

We also invite you to download your own copy of the ASTM B117 document below.

The Appendix below provides additional information about numerous material tests carried out at Micom Laboratories including classification of corrosion test results according to ASTM D610 .

We also invite you to download our brochure to learn more about our Paint, Coating and Polymer testing services.

If you have any questions about the ASTM B117 test, we invite you to contact our material testing lab today. It will be our pleasure to answer your questions and help you with your custom material testing requirements.

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