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INTERNATIONAL TUNGSTEN INDUSTRY ASSOCIATION

Information on tungsten: sources, properties and uses

Electrical Contact Materials

Tungsten runs across our life when strong currents are switched; the best example is the car horn.  Tungsten electrodes are also used for ignition contact breakers, voltage regulators and safety switches.

Sintered or infiltrated tungsten-copper, tungsten-silver or tungsten carbide-silver contacts are used in high performance switches, for the high voltage (72.5-800kV), medium voltage (5-38kV) and low voltage (<1kV) range.  The magnitude of switching currents can attain 100kA, and arc temperatures in excess of 10,000K can prevail for milliseconds during switching.

Nozzles and electrodes for plasma spray guns, resistance welding or spark erosion are made of W-Cu, W-CuNi or W-Ag.