ASTM B117 is a standard commonly used in many industries to check the corrosion resistance of materials and surface coatings. Industries such as building products and construction, transportation, aerospace, infrastructure, and defense utilize ASTM B117 for salt spray testing. Knowing more about how this standard works helps stakeholders and companies to plan for essential quality assessments.


What is ASTM B117?

ASTM B117 is a test that accelerates the corrosion process in order to observe how a material stands up to rust and corrosion in a hot and humid environment with salt in the air (e.g. marine or coastal environment). As such, ASTM B117 testing is often referred to as a “salt spray test” or a “salt fog test.”


How It Works

In testing to the ASTM B117 standard, test materials are exposed to an atomized saltwater solution inside an enclosed chamber. This chamber is maintained at specified temperature and humidity conditions, creating a highly corrosive environment. While maintaining a temperature of 95°F inside the chamber, a humidifying tower also creates a relative humidity condition approaching 100%.


Test Duration

While ASTM B117 itself does not specify a required duration, other specifications often prescribe the number of hours of exposure required for a specific evaluation. For example, ASTM A1003/ASTM A1004 indicate that metallic-coated, nonstructural cold-formed steel framing members should undergo 75 hours of ASTM B117 exposure. Any duration can be used; however, it should be noted that correlating ASTM B117 results to real-world conditions is not part of this test standard and is difficult to predict.


Test Results

There are several options for assessing the performance of materials after ASTM B117 exposure. A visual inspection can be conducted, typically using ASTM D610. Using ASTM D1654 (scribing), a scratch is placed in the coating to the underlying metal to see how corrosion develops. Additionally, using ASTM D3359 (adhesion by tape), it can be determined how well a coating adheres to metal and how far the corrosion crept.


What is ASTM B117 Used For?

For the construction industry, building products such as cold-formed steel framing (studs and track), fasteners (nails and screws), and other metallic products with protective coatings are often required to be evaluated for corrosion resistance. Sometimes even plastic materials are tested.

In the automotive field, ASTM B117 is used to simulate environments to determine how road salt would affect auto parts.

Applying ASTM B117 to aircraft design helps with key safety protocols by assisting the planners in identifying when and how corrosion might compromise parts.

Another significant use of ASTM B117 is in utility infrastructures, such as water and sewer implementation. ASTM B117 can be used to determine the corrosion resistance of metal pipes.


Companies who need testing to ASTM B117 and other standards can get assistance from ICC NTA, who has the experience and an excellent track record with advising clients on how these standards work and how to achieve best practices within a given industry. Get connected with ICC NTA and our wealth of expertise in standards for building and construction, fire safety, and other aspects of the world of quality assurance and assessment.


About ICC NTA, LLC: As an accredited third-party agency and part of the International Code Council (ICC) family of solutions, NTA provides code evaluation, product certification, inspection, engineering, plan review, and testing services, as well as independent quality and standards compliance verification for building product manufacturers. With offices, testing labs, and training facilities in Nappanee, Indiana, and Bryan, Texas, NTA serves residential and commercial builders, code officials, manufacturers, and suppliers throughout the building industry.