Tungsten wire can vary according to its size, use, and appearance and the most common assortment way is depending on its chemical content.
Pure Tungsten Wire
According to the different application, pure tungsten wire can be classified into two types. The first type wire typically used in hospital devices such as LEEP electrodes, thermionic emitters, and corona generation with the non-sagging properties . Another type can be used for products that use glass-to-metal seals, such as vacuum tubes, reed switches, and incandescent light bulbs. These wires usually content 99.95 percent W and are excellent heat and electrical conductors. Wires of pure tungsten are usually more than 20 inches (5.08 millimeters). They are resistant to heat so that some manufactured tungsten wires can have a melting point of about 6,150° Fahrenheit about 3,400° Celsius.
Tungsten Thorium Wire
To produce a specialized wire, chemical element thorium can be added into tungsten. Different type content different amount, some content one percent while others content two percent or more. These wires can be manufactured into thread-like thinness and used for microwave ovens and plasma wielding. This tungsten wire type is said to be 50 percent more effective as an electric conductor.
Tungsten Rhenium Wire
Tungsten wire can also be mixed in with element called rhenium. Tungsten and rhenium can effectively create efficient metal alloys because both have very high melting points respectively about 6,192°F (3,422°C) and 5,767°F (3,186°C). This type of wire is used for the situation where very high heat is required. Tungsten-rhenium wires are categorized based on the percentage of rhenium included. WR30 has 3 percent rhenium and WR200 has 20 percent. All of these types are highly resilient, strong, and resistant to corrosion.
Tungsten Molybdenum Wire
Other element used to make alloy wires is molybdenum, as it also has a high melting point of 4,753°F (2,623°C). Both molybdenum and tungsten have very similar chemical characteristics that make them ideal for alloying. This type of tungsten wire can be use in furnaces, cars, and even aircrafts, as it is resistant to heat and corrosion.
Doped Tungsten Wire
Another type of tungsten wire is the doped tungsten wire. The word doped means some elements have been added to somehow strengthen its strength and resistance. Doping also alters its chemical structure, and the wire will have an interlocking composition that makes it stronger. This type of wire ranges from .001 inches (.0254 millimeters) to .250 inches (6.35 millimeters) in thickness and is used for wire and lamp filaments. The three elements of potassium, aluminum and silicon are commonly used in doped tungsten wires.