What is Tungsten? | Tungsten characteristics and processing examples

On this page, we will explain the characteristics and uses of tungsten, which is one of the processing materials, and the processing of tungsten in TDC.

What is tungsten

Tungsten is a rare metal with a silver-gray appearance.

It has the meaning of “heavy stone” in Swedish, and as the meaning suggests, it is about 2.5 times as heavy as iron, 1.7 times as heavy as lead, and about the same weight as gold.
The chemical symbol for tungsten, “W”, comes from the German name Wolfram.

It has the highest melting point and the lowest coefficient of thermal expansion among metals, so it can easily maintain its shape even in a high-temperature environment, and has heat resistance enough to be used for parts of high-temperature furnaces.

It is also used as a material for cutting tools because its hardness increases when combined with carbon.

Tungsten characteristics, characteristics and properties

The main characteristics of tungsten are as follows.

• High melting point and heat resistant

Tungsten has a melting point of 3653K, which is the highest melting point of any single metal, and its low coefficient of thermal expansion makes it excellent in shape stability even in high-temperature environments.

• have a large electrical resistance

Tungsten has a higher electrical resistance than other metals. Due to its heat resistance, it is often used as filament for light bulbs.

• Heavier than iron and lead

Tungsten has a specific gravity of 19.3, about the same weight as gold. It is 2.5 times heavier than iron and 1.7 times heavier than lead.

• High radiation shielding ability

Tungsten has much higher radiation shielding ability than lead, so it is used as a shielding material for X-ray irradiation equipment.

• high hardness

Tungsten has a high hardness, and when combined with carbon, it becomes a harder material.

Cemented carbide, which is a combination of tungsten carbide (tungsten carbide) and cobalt, is second only to diamond in hardness and is used as a metal cutting tool. On the other hand, it is also characterized by being difficult to process because it is a hard material.

Physical Properties of Tungsten (Element Symbol W)

density (mg/m3)	293K：19.3
Melting point(K)	3653
Boiling point(K)	5800
electrical resistivity(10-8Ωm)	293K：5.4
specific heat (J/kgK)	273-373K：138
thermal conductivity(W/mK)	273-373K：174
coefficient of linear expansion(10-6/K)	273-373K：4.5 293-2273K：5.4

Difference Between Tungsten and Molybdenum

Molybdenum is a material that has similar properties to tungsten. Both tungsten and molybdenum are materials that fall under the category of rare metals, and in addition to having similar properties such as a high melting point, thermal expansion, and specific gravity, they are also characterized by similar good thermal conductivity.

The difference between tungsten and molybdenum is ease of processing and strength of resistance to heat.

Molybdenum has better workability and has workability equivalent to stainless steel. On the other hand, tungsten is a difficult material to process due to its extremely high hardness.

As for heat resistance, molybdenum has a lower melting point and boiling point than molybdenum, so tungsten is often used as a material for parts used in high-temperature locations.

Applications of Tungsten

Due to its high melting point, electrical resistance, and hardness, tungsten is used in various fields and industries such as tools, automobiles, medicine, and lighting.

The main uses are as follows.

• cutting tools
• resistance welding electrodes
• TIG electrode rod
• Heat-resistant structural parts for high-temperature furnaces
• weight for fishing tackle
• balance weight
• light bulb filament
• Cores of armor-piercing and artillery shells
• Radiation shielding material
• catheter treatment instrument

Tungsten processing example at TDC

Introduces typical examples of tungsten polishing at TDC.

Tungsten polishing example 1: “Slit blade”

• Size: about 30×40
• Specifications/Accuracy: Example) Straightness 0.2um, Flatness 0.1um
• Processing details: We also accept new production and correction polishing of slit blades. It is possible to manufacture with the desired accuracy.

Tungsten polishing example 2: “Test piece/test piece”

• Size: Any size you want
• Specifications/Accuracy: Surface roughness Ra0.001, flatness 0.001, parallelism 0.001, etc.
• Processing details: We manufacture test specimens and test pieces with the desired size, shape, and accuracy. We will take care of the materials for you.

Tungsten polishing example 3: “Tungsten mirror foil”

• Size: 50x50x0.05
• Specifications/accuracy: thinning from 0.05 to 0.02, mirror finish Ra1nm or less
• Processing details: We accept requests for mirror surface processing of foil from sheet size to long size.

Please contact TDC for tungsten polishing.

Tungsten is a heat-resistant and extremely hard material, so it is often used in cutting tools.

At TDC, we are able to process tungsten, which is a difficult-to-cut material, with our processing know-how for each material and our accumulated processing technology.

If you have a tungsten processing project that other companies have refused, please do not hesitate to contact TDC.

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