Industries · Switchgear
Contact Materials for Switchgear: Silver Contacts, Clad Metal and Copper
Relays, contactors, switches and circuit breakers depend on contact materials that resist arcing and welding, plus the conductors and springs around them. VAN INTERTRADE supplies Longsun silver electrical contacts, clad metal and standard copper alloys for switchgear.
What switching contacts face
Every time a contact opens or closes under load, an arc forms. Over many operations the arc erodes the contact face, can weld the contacts together and raises contact resistance. Silver is the base of most contact materials but it is expensive, so the material and the structure of the contact are chosen together.
Materials for switchgear
- Electrical Contacts
Solid, bi-metal and tri-metal rivets, buttons and wire in AgNi, AgSnO2 and AgCdO, plus AgW and CuW for high-power switching.
- Clad Metal
Ag/Cu puts silver only on the contact surface over a copper base, cutting the silver content of the part.
- Standard Copper Alloys
C5210 phosphor bronze for springs and switch and relay contacts, and C1100 for busbars and switchboard conductors.
Frequently asked questions
- Which contact material suits high-power switching?
- AgW and CuW, powder-metallurgy tungsten composites with high arc and erosion resistance, used for breakers and high-power switching.
- Is there a cadmium-free alternative to AgCdO?
- Yes. AgSnO2 has good resistance to welding and arc erosion and is the usual cadmium-free alternative. Check your destination market's rules before choosing.
- How can I use less silver in a contact?
- Choose a bi-metal or tri-metal rivet, which puts the silver alloy only on the contact face over a copper body, or Ag/Cu clad metal, which carries silver only on the contact surface.
Choosing a material for switchgear?
Tell us the part, the grade or form you have in mind, the size and the quantity, and we will send a quotation.