General:
This test is commonly used for quality control and product specification to ensure that greases are non-corrosive to copper and copper-containing components found in bearings, electrical equipment, and mechanical systems.
Precision:
The method provides repeatability and reproducibility values based on interlaboratory studies. Since the result is reported as a visual corrosion classification (1a to 4c).
Test:
A polished copper strip is completely coated with the test grease and heated at a specified temperature, typically 100 °C for 24 hours. After exposure, the grease is removed and the copper strip is visually compared with the ASTM Copper Strip Corrosion Standard to assign a corrosion rating. Lower ratings (e.g., 1a or 1b) indicate little or no corrosion, while higher ratings indicate increasing levels of tarnish or corrosion.