NSS vs CASS vs AASS

NSS, CASS, and AASS explained side-by-side. Understand which salt spray test method is right for your substrate, coating, and industry requirement.

NSS, CASS, and AASS are related corrosion methods, but they are not interchangeable. The correct test depends on substrate, coating system, applicable standard, and how quickly a meaningful result needs to be generated.

Neutral Salt Spray

  • The broadest default method for plated, galvanized, and powder-coated parts.
  • Usually the starting point when a general salt fog requirement is specified.

Copper-Accelerated Salt Spray

  • Used for aluminium alloys, decorative chrome, and accelerated screening needs.
  • More aggressive than NSS and used where faster corrosion differentiation is required.

Acetic Acid Salt Spray

  • Applied to some organic coatings and aerospace or military finish systems.
  • Chosen when the referenced material or product standard explicitly calls for it.