Comparison of Common Fastener Surface Treatment Technologies to Improve Anti-rust and Wear Resistance

Suitable surface treatment is essential for fasteners serving in humid, acidic and outdoor environments for a long time. Various coating technologies differ greatly in anti-corrosion lifespan, cost, friction coefficient and hydrogen embrittlement risk. Improper selection will lead to premature rust failure.

Electro galvanizing features moderate cost and bright surface for indoor applications. Dacromet coating offers excellent salt spray resistance without chromium and reduces hydrogen embrittlement risk, ideal for high-strength fasteners. Hot-dip galvanizing forms thick coating for steel structures and outdoor projects. Black oxide provides limited corrosion resistance and is mainly used for internal components.

Electroplating on high-strength alloy steel screws may cause hydrogen embrittlement and delayed fracture. Post-plating baking for hydrogen removal is mandatory. Manufacturers shall select coating solutions according to working environment, load grade and budget.

Driven by photovoltaic and rail transit industries, demand for long-term anti-corrosion surface treatment keeps rising. Eco-friendly and high weather-resistant coating technologies will become an important trend in the fastener industry.