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INTERNATIONAL TUNGSTEN INDUSTRY ASSOCIATION
Information on tungsten: sources, properties and uses
Lamp Industry
Since the beginning of the 20th century, tungsten has illuminated the world, and the use of tungsten filaments in light bulbs has become a matter of course, in particular in domestic lighting. Tungsten is used in this application because of its extremely high melting temperature (~3,695 K), low vapour pressure, high stiffness and excellent creep resistance at elevated temperatures.
The image above, representing permanent lights on the Earth’s surface, was created with data from the Defense Meteorological Satellite Program (DMSP). Even more than 100 years after the invention of the tungsten light bulb, some areas still remain dark.
About 4% of the annual tungsten production is consumed by the lighting industry, which uses about 15% of the global electric power produced worldwide.
The largest market is still for incandescent lamps (2007: about 12 billion lamps) but more than 70% of artificial lighting is generated today by discharge lamps, and this portion is steadily increasing. Tungsten is used in the form of wires, coils, and coiled coils in incandescent lamps, and as electrode in low- and high-pressure discharge lamps.