Relay Contact Materials

I’ve made this quick reference guide to help pick the contact materials for your relay. The abbreviations are those used by Finder.

AbbreviationMaterialBenefitsDownsidesUsed for
AgNiSilver NickelLow Cost, popularEverything. Resistive Loads, slightly inductive loads
AgNi + AuSilver Nickel + Gold platedLower contact resistanceLow power loads. Use at medium power will erode the gold and turn it into an AgNi contact.
AgCdOSilver Cadmium OxideGood Resistance to contact weldingCadmium is toxic, and is slowly being banned.Heavy Inductive Loads with large inrush currents
AgSnO2Silver Tin
Oxide
Best Resistance to contact weldingCapacitive Loads with very large inrush currents (more than twice as much as AgCdO

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