ASTM B368 is the standard test method for Copper-Accelerated Acetic Acid-Salt Spray (Fog) Testing, commonly called the CASS test. It provides a controlled corrosion test environment used to evaluate how materials or finishes respond to aggressive salt spray exposure. This makes the standard valuable for comparing performance, supporting quality control, and checking whether a surface treatment or coating holds up under demanding conditions.

Purpose of ASTM B368

The purpose of ASTM B368 is to define a repeatable method for copper-accelerated acetic acid-salt spray testing. By specifying a controlled fog environment, the standard helps users generate consistent corrosion test results that can be compared across batches, suppliers, or time periods. It is generally used when a more severe accelerated corrosion exposure is needed to assess relative resistance and surface durability. The standard supports disciplined testing practices and more reliable interpretation of results.

Common use cases of ASTM B368

ASTM B368 is commonly used in laboratory and quality assurance settings where coated metals, plated parts, or treated surfaces need accelerated corrosion evaluation. It is often applied during product development, incoming inspection, qualification testing, and routine verification of finish performance. Because the CASS test is designed for controlled exposure, it is useful when comparing similar finishes or confirming that a surface treatment meets expected technical requirements.

Why ASTM B368 matters

ASTM B368 matters because it gives organizations a recognized framework for corrosion testing that improves consistency and communication. Using a defined standard helps reduce ambiguity in procurement, supplier evaluation, and compliance checks. It also supports better risk reduction by making it easier to identify weak finishes or process variation before products enter service. For teams responsible for testing and quality control, ASTM B368 helps ensure results are more repeatable and easier to defend technically.

• Controlled copper-accelerated salt spray exposure
• Accelerated corrosion comparison method
• Useful for coated and plated surfaces
• Supports quality control and qualification testing
• Helps standardize test reporting and review