Cadmium vs. Zinc Plating: Which Finish Beats Corrosion & Cost?
Cadmium plating is a silver-gray electroplated coating that resists saltwater corrosion; zinc plating is a bluish-white layer that fights rust with lower toxicity.
Buyers often grab whichever finish is in stock, yet salt-spray tests show cadmium surviving 1,000+ hours while zinc taps out near 200. That gap drives aerospace to pay triple for cadmium, while bike builders stick with cheaper zinc and repaint sooner.
Key Differences
Cadmium offers superior marine corrosion resistance and lubricity for threads; zinc is non-toxic, 30–50 % cheaper, and meets RoHS for consumer goods.
Which One Should You Choose?
Pick cadmium for aircraft, marine hardware, or high-reliability electronics. Choose zinc for automotive brackets, outdoor furniture, and any project needing eco-friendly, low-cost rust protection.
Can I switch from cadmium to zinc on aerospace parts?
Only if the spec allows; most aviation standards still require cadmium for critical fasteners.
Does zinc plating need extra coating?
A chromate conversion or powder coat can double zinc’s salt-spray life, especially near roads that salt in winter.