Pure tungsten is steel-gray to tin-white and is a hard metal. It is brittle and hard to work when impure. Very pure tungsten can be cut with a hacksaw, forged, spun, drawn, and extruded. Tungsten has a number of valuable properties that make it an extensively used commodity, including:
• Highest melting point (3,422°C 6,192°F)
• Highest boiling point (5,660°C 10,210°F)
• Lowest vapor pressure and highest tensile strength when >1,650°C (3,000°F)
• Highest Density 19.30 g/cm3
• Excellent resistance to corrosion
• High hardness when alloyed
High melting point, high density, hardness of carbide and readiness of superalloys enable tungsten and its alloys to be used extensively in as many as industries like machining, mining, petroleum, lighting, vacuum, chemical, aerospace, nuclear, medical, electrical, and electronics.
Tungsten metal forms a protective oxide when exposed to air but can be oxidized at high temperature. Its corrosion resistance is excellent and it can only be attacked slightly by most mineral acids. When alloyed in small quantities with steel, it greatly increases its hardness. The thermal expansion is about the same as borosilicate glass, which makes the metal useful for glass-to-metal seals.