Tungsten

Tungsten has the highest melting point (3410 degrees C) and lowest vapor pressure of all metals, and at temperatures over 1650°C has the highest tensile strength. It has a density of 19.3 gm/cc. It has excellent corrosion resistance and is attacked only slightly by most mineral acids.

Historically, tungsten has been used as a filament for the lamp industry. Tungsten has many attributes that prove beneficial in vacuum furnaces. In very high heat environments, tungsten maintains its strength (it is the best performing metal of the common refractory metals in terms of strength). Tungsten also offers good electrical resistivity, allowing for it to be used for many applications. Its high density and strength make it an extremely versatile metal.