Tungsten is a naturally occurring metal. Its atomic number on the periodic table is 74, and it is sometimes known as "wolfram." The main mineral from which it is derived is wolframite ore. From wolframite, tungsten gets its letter on the periodic table, W. In addition to wolframite, tungsten can be derived from the mineral scheelite. Tungsten’s coloring varies between a steel gray to a tin white. Tungsten is known for its tensile strength, high density and extreme temperature resistance. It has the highest melting point (6192 °F) and lowest vapor pressure of any known non-alloyed metal. Also, it is the heaviest chemical element considered usable.
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Benefits of Tungsten
Tungsten offers its users many benefits. First, it has low toxicity, especially when compared to other metals. This is good for both people and the environment. Second, tungsten is recyclable. This lowers costs and eases the toll of mining. Tungsten is also very strong; when combined with carbon, only diamonds are stronger. Even as a raw material, it is still as strong as titanium.
The History of Tungsten
Tungsten was first discovered during the 1500s, when miners discovered a mineral containing it while working in the Erz Mountains. These mountains are located in Central Europe, where they form a natural border between modern-day Germany and the Czech Republic. The miners did not know what the mineral was, only that it irritated them because it caused slagging and interfered with the reduction of the tin mineral they were mining. They nicknamed it "wolfrahm," meaning "wolf froth" because they noted that 1) it devoured the tin like a wolf would a sheep, 2) it foamed on the surface of the tin during smelting and 3) the mineral was black and had a hairy texture. In 1546, Georgius Agricola referred to this mineral in his book De Natura Fossilium as "spuma lupi," which is Latin for "wolf froth" or "wolf cream."
- During the 1700’s
- Tungsten is actually named after another tungsten ore, now known as scheelite. It comes from the Swedish "tung sten," which translates to "heavy stone." Swedish mineralogist and chemist, Axel Fredrik Cronstedt, named this tungsten ore in 1758. Cronstedt was very excited about his discovery, and believed he had found a new element. He could not, however, prove it. Instead, the first person to isolate tungsten was his countryman, Carl Wilhelm Scheele. Scheele accomplished this about 20 years later, in 1781. Two years later, two Spanish brothers and chemists, Fausto and Juan José de Elhuyar y de Suvisa, successfully reduced wolframite to tungsten.
- During the 1800’s
- In 1855, scientists first began attempting to make tungsten steel. They were able to do so, patenting the first tungsten-steels in 1858, but no one was interested in them because they were so expensive. It was not until late in that century that engineers were able to find an industrial use for tungsten. This was the hardening and alloying of steel. After this, tungsten steels, marketed as high speed steels, became a hit. They made their debut at the 1900 World Exhibition in Paris, and they’re popular to this day.
- During the 1900’s
- In 1903, American engineer and physicist W.D. Coolidge created a ductile tungsten wire and started the practice of tungsten powder metallurgy. He did so by doping (adding a trace impurity) tungsten oxide before he reduced it, thus creating a metal powder. Next, he pressed, sintered and forged the tungsten powder into thin tungsten rods. He completed the process by drawing fine wire from the rods. Using Coolidge’s tungsten filaments, in 1904, European inventors developed the first tungsten light bulb. They were far more efficient than the light bulbs powered by carbon filaments, and quickly replaced them.
- About 20 years later, in 1923, a group of German scientists, most notably Franz Skaupy and K. Schröter, working for a company called Osram Studiengesellschaft, developed cemented carbide, sometimes called hardmetal. The original patent holder, Osram Studiengesellschaft, failed to grasp the gravity of the invention, and let the patent expire. In 1926, the company allowed the patent to be sold to another company, Friedrich Krupp AG. This purchase proved quite lucrative for Krupp, as cemented carbide was used heavily during World War II.
- Since then, tungsten and tungsten alloys have continued to prove themselves useful. Though the tungsten light bulb fell out of favor around 1950, tungsten gained many other applications. For example, in 1969, scientists began producing corrosion-resistant tungsten coatings. Today, it is more important than ever in high-tech and high-intensity industries like semiconductor and aerospace.
Applications of Tungsten
Tungsten metal's high melting point and hardness at high temperatures make it very useful in various high-temperature applications, such as: light bulb, cathode tube, vacuum tube filament, arc welding, gas tungsten arc welding and electric discharge machining.
Some of the many different industries in which tungsten is used include: construction, aerospace, engineering, semiconductor, consumer products, jewelry, laser welding, industrial machinery, mining, electric, electronics, lighting and healthcare.
Design of Tungsten
Tungsten metals and alloys are very electrically and thermally conductive, making them useful in electrical applications. They also have excellent resistance to corrosion. Despite these unique and useful properties, tungsten is very brittle in its raw material state and can be hard to work with, especially under pressure.
Tungsten Production Process
To make tungsten products, manufacturers generally start by sintering or molding the tungsten and tungsten alloys into billets in the form of solid blocks or bars (suppliers listed here). They then fabricate them into tungsten bar, tungsten sheet, tungsten plate, tungsten foil, rod or tungsten wire forms. They do this by way of drawing, grounding, molding and die cutting, among others. Some products require further processing.
Tungsten products are sold in three different conditions: black, which maintains a coating of lubricant and oxide; cleaned, in which the coating has been removed with chemicals; and ground, in which the tungsten has been machined with diamond or silicon carbide tools to remove the coating and achieve a certain smoothness and diameter.
Types of Tungsten
Tungsten suppliers offer tungsten in five main forms: tungsten carbide, cemented carbide, alloyed tungsten (including heavy metal tungsten alloy), pure tungsten and tungsten-based chemicals. Tungsten alloys are also divided by classes defined by the nominal weight of tungsten and ultimate tensile strength.
- Tungsten Carbide
- Half carbon, half tungsten. It is extremely strong and extremely wear resistant. This inorganic chemical compound is twice as hard as any high grade steel and much denser than titanium or steel. There are over 20 different grades of tungsten carbide powder, which have differing grain size, hardness, tensile strength and melting point properties.
- Tungsten manufacturers press and sinter it to become all kinds of strong and durable metal products, parts and tools. Tungsten carbide and crushed tungsten carbide are very useful in the metalworking, mining and construction industries. In fact, 60% of all tungsten carbide products are manufactured for applications within these industries.
- Cemented Carbide
- One of the most common tungsten alloys. It is tungsten carbide alloyed with cobalt, which acts as a binder to form the cement. This type of tungsten is used in cutting applications. The cobalt counteracts tungsten's tendency to become brittle under higher pressures, allowing it to be used in structural applications. These wear-resistant materials are used primarily in the metalworking, mining and construction industries.
- Alloyed Tungsten
- A general term, referring to those many different varieties of tungsten mixed with any number of different metals. (Mostly, these include copper and iron.) Most often, tungsten suppliers offer tungsten alloys, such as copper tungsten, and tungsten carbide for industrial and commercial applications.
- Heavy-metal Tungsten Alloys
- Contain very little amounts of another substance; they are at least 90% tungsten. Manufacturers often pair heavy metal tungsten alloys with a small amount of thorium oxide (around 2%) to perform gas tungsten arc welding. Using ThO2 enhances the thermionic electron emission, which improves the starting characteristics of gas tungsten arc welding electrodes.
- Pure Tungsten
- Extremely electrically conductive and primarily used in electrical applications. In electronics, pure tungsten is used to connect materials on a circuit panel.
- Tungsten-based Chemicals
- The most rare tungsten variety. They are used to make organic dyes, pigment phosphors and x-ray screens.
Products Produced from Tungsten
Tungsten materials are used to make a wide range of products, including: tungsten electrodes, light bulbs, drilling equipment, tools, industrial machinery components, weapons, tungsten boats (used in vacuum evaporation and material coating), construction equipment and x-ray screens. Tungsten alloys are also used in armaments, heat sinks, turbine blades, industrial parts and high-density items, like ballasts and weights. Furthermore, they may be made into a wear-resistant coating that users can apply to their tools in order to extend their lives by many years.
Tungsten electrodes are one of the most common tungsten products. Used in electric arc welding, they transfer high voltages of electric current to two separate sheets of metal. The heat generated from the electricity causes the metal parts to melt together, thus forming a weld. They are also often used in electric discharge machining and gas tungsten arc welding.
Things to Consider When Choosing Tungsten
If you are looking to invest in tungsten products, you need to partner with an honest and reliable tungsten supplier, such as those we’ve listed on this page. Before partnering with anyone, you need to make sure that they know all of your specifications, including your budget, timeframe, delivery requirements and standard requirements. You also need to make sure that they can deliver the quality and volume you need. Different manufacturers have different capacity production capabilities. In short, they need to not only be a high quality manufacturer, but a high quality manufacturer that can properly serve you.
Find out if one of those manufacturers on this page is the right one for you by checking out the interactive profiles we have provided, as well as their respective websites. Pick out three or four to whom you’d like to speak directly, and reach out. Once you’ve spoken with each of them, compare and contrast their answers, and pick the right one for you.
Overseas Market of Tungsten
Because tungsten has such a wide range of purposes, it is in high demand for industry and commercial applications. About 45,000 tons of tungsten is mined each year, mostly in China and Russia. Other tungsten-producing countries include: Portugal, Austria, Peru and Bolivia. Tungsten production in the USA today is virtually non-existent. This is mainly due to environmental concerns, the low price of imports and ever-changing governmental policies and restrictions. Fortunately, because tungsten is so inexpensive to import, American companies can still provide customers with tungsten products at reasonable prices. Plus, tungsten is recyclable, so manufacturers can use it over and over again without.
There are many other advantages to working with a stateside manufacturer. These include: ease of communication, quicker deliveries, less red tape (tariffs, higher delivery costs, etc.) and the assurance that the company fully understands all laws and regulations associated with tungsten products in the United States. We believe, considering all of these advantages, that it is still quite worth it to work with an American manufacturer, rather than one located overseas.
- A solid solution or homogenous mixture of two or more metals or elements.
- Easily broken when stressed. Brittle substances show very little strain or deformity before fracturing.
- A tiny metal wire, usually composed of tungsten, which converts electricity to light within a light bulb.
- Melting Point
- The temperature at which a solid substance becomes a liquid.
- An alloy which has excellent strength, hardness and resistance to corrosion. Usually has a metal base of nickel, cobalt or iron.
- Tensile Strength
- In engineering, the point at which a material fails under applied stress or pressure.
- An alternative term for the metal tungsten. This term is derived from wolframite ore, the primary source of tungsten metal.