Salt spray testing is a common way to evaluate fastener corrosion resistance, with significant differences across coating processes and thicknesses. Understanding test standards and class comparison helps purchasers and engineers select corrosion protection correctly.
Neutral salt spray (NSS) is performed per GB/T 10125, ISO 9227 and similar standards, typically 5% NaCl solution at 35°C, pH 6.5-7.2. Acetic acid salt spray (AASS) and copper-accelerated acetic acid salt spray (CASS) evaluate specific coatings.
Regular electroplated zinc at 8-12 μm generally passes 72-96 hours of NSS. Dacromet and zinc-aluminum coatings typically reach 240-720 hours. Hot-dip galvanizing and stainless steel offer higher resistance, subject to coating system and process.
Choose electroplated zinc for indoor electronics, Dacromet, hot-dip galvanizing or stainless steel for coastal and outdoor projects, and combine sealing and maintenance plans for high-salinity environments. Match test results with service environments to avoid over-design on a single indicator.
The comprehensive fastener platform arranges salt spray tests and reports per customer standards.