Despite the growing market for modern LEDs, many homes still use traditional incandescent light bulbs – so every time you turn them on, you’re making use of a tungsten filament. Most people know about this common use of the metal, but many might wonder: what exactly is tungsten?
Unless you’re an expert in refractory metals, which tungsten happens to be one of, you may not know about all the unique properties of this element that make it so useful. This blog can fill you in on everything you need to know about tungsten, from its appearance to its various applications.
A brief history of tungsten
Pure tungsten is a silvery-white shiny metal, also known by the Latin name wolfram, which is where the element’s chemical symbol of W comes from. It sits below chromium and molybdenum in the same column of the periodic table, with all 3 being transition metals as well as refractory metals.
Almost as hard as diamond, tungsten has a very high melting point and heavy density. Fun fact: the element’s name is based on the Swedish words tung sten, which mean ‘heavy stone’. As it’s found in compounds in the Earth’s crust, not as a free metal, tungsten must be purified before it can be used.
According to the Royal Society of Chemistry, this element was officially discovered in 1783 by two Spanish brothers who first synthesised it from tungsten-based minerals (scheelite and wolframite).
Scheelite was first found in an iron mine in Sweden in 1779, while wolframite was found in a tin mine in Germany in 1781. However, the element was known of and even used earlier than this –porcelain makers were using a tungsten-based peach pigment in China more than 350 years ago.
According to Britannica, the rarity of tungsten is around 1.5g per 1 tonne (1000g) of rock, or 1.5 parts per million. Over 80% of the world’s tungsten supply is still mined and produced in China.
Tungsten’s chemical properties
Tungsten is the strongest natural metal on the planet, with the highest heat resistance and tensile strength of any pure metal. In fact, it has the highest melting point of all the refractory metals. Its low thermal expansion and high resistance to acidic corrosion make it useful for many different applications. Here’s a quick rundown of tungsten’s key properties:
- Atomic number: 74
- Atomic mass: 183.85g per mole
- Density: 19.3g per cm3
- Melting point: 3410°C
- Boiling point: 5660°C
- Mohs hardness: 7.5/10
Being a good electrical conductor and inert to oxidisation at average temperatures are also valuable qualities of tungsten. It can be soft and brittle in its pure form, but this also means that it’s ductile and malleable. Creating tungsten compounds makes it tougher – for example, tungsten carbide has a Mohs hardness of 9, making it almost as scratch-resistant as diamond at the highest rating of 10.
What is tungsten used for?
While lots of people know about tungsten in light bulbs, it’s not necessarily a household name like some other elements. There are hundreds of uses for tungsten across many different industries, with a variety of tungsten compounds producing different qualities ideal for different purposes.
Not only are you likely to be relying on tungsten every time you flick a light switch, but it’s also commonly used in television tubes and X-ray machines. This element makes up the electron beam targets, but is also an alternative to lead for radiation shields in medical and industrial imaging.
As a relatively inert conductor, tungsten is useful for many metal components in electronics. It’s frequently found in electrodes, cathodes, oscillators, thermocouples, and metallic films. Its high temperature resistance also makes it suitable for use in the aerospace and construction industries.
Extremely hard alloys like tungsten carbide are popular for producing machining parts, such as dies, drill bits, and gauges. Its strength makes it an excellent material for grinding, milling, and cutting tools, which is why it’s often used in metalworking and mining. Other high-density tungsten alloys are used in racing car ballast, aircraft turbine blades and engine valves, and rocket engine nozzles.
As a counterweight material, tungsten can also be found in sporting equipment, from golf clubs and dart barrels to fishing sinkers and shotgun pellets. It has military uses, as well, in armour-piercing ballistics like bullets and missiles. On the more everyday end of the scale, tungsten’s density ad scratch resistance makes it an attractive alternative material for jewellery, such as wedding rings.
There are plenty of chemical applications for tungsten, as well. For example, it can be used as a catalyst or lubricant when synthesising products like gasoline and paint pigments. You might even find it in yarn-like form, woven into ceramic and plastic and other composites to reinforce them.
Where can you buy tungsten metal?
As you can see, tungsten is a very interesting and highly useful element, and it’s available in many different forms. If you’re looking to buy tungsten, or metal parts manufactured with tungsten metal, you should order from a professional supplier – ensuring you receive high-quality tungsten products.
From wire and sheets to bars and billets, you should be able to find not just tungsten, but the full selection of refractory metals for sale. This may be in standard sizes, or made-to-order according to your specifications. It’s always a good idea to ask the experts before you order tungsten from them.