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Tungsten Rod

Tungsten Rod

Date posted: February 13, 2017 // Tungsten

Originally known as wolfram and confirmed by the use of the uppercase letter “W” as its chemical symbol, tungsten was first isolated in the late 1700s by two Spanish brothers. Its modern name derives from the Swedish language and means “heavy stone”, but it is its hardness and high melting point that have led to its widespread use in industry, as well as stirring the interest of the military. With the highest melting point of any metal and the greatest tensile strength at high temperatures, when fashioned in the form of a rod, this metal has a number of uses that are mostly constructive, but at least one that has the power to destroy.

First theorised during the cold war, an extremely large tungsten rod, directed to a target on the earth’s surface from an orbiting platform, was proposed as a weapon able to deliver a kinetic impact with the destructive power of a small nuclear bomb, but without the accompanying risk of a widespread radioactive fallout. The metal would indeed prove particularly effective for such a purpose, due to its exceptional hardness, high density and ability to resist atmospheric friction without burning up. Whether such weapons have been or will be developed remains a matter of conjecture, but these same properties are responsible for the metal’s more constructive applications that offer many benefits to manufacturers and consumers.

Along with niobium, molybdenum, tantalum and rhenium, tungsten is one of the five major refractory metals, and is valued for its exceptional resistance to the effects of high temperature, and mechanical wear and tear. These properties make it an ideal choice for use as the filaments in halogen lamps or, in the form of its carbide, for the manufacture of tough drill bits, as well as the use in high-temperature welding applications. In the process known as GTAW or TIG welding, a tungsten rod is electrically heated whilst shielded within an atmosphere of inert gas, such as argon or helium. Protected by its high melting point and superior electrical conductivity, it serves as a non-consumable electrode, capable of providing temperatures of up to 6 100°C to create the weld.

These qualities make this particular refractory metal an ideal choice for use as an electrode when welding non-ferrous metals, such as copper alloys and aluminium, and can also be employed in automated plasma arc welding.

For these and other applications, a tungsten rod must be of exceptionally high quality and completely free of any impurities that may diminish its natural properties. LIT Africa sources these and other world-class refractory metal products for use in South Africa’s industries from the prestigious Austrian manufacturer, Plansee.