The impure metal is brittle and can be worked only with difficulty. Tungsten has the highest melfing point and lowest vapor pressure of all metals, and at temperatures over 16500C has the highest tensile strength. The metal oxidizes in air and must be protected at elevated tempera- tures. It has excellent corrosion resistance and is attacked only slightly by most mineral acids. High-speed tool steels, Hastelloys, Stellite, and many other alloys contain tungsten.
Tungsten carbide is of great importance to the metalworking, mining, and petroleum industries.
Tungsten disulfide is a dry, high-temperature lubricant, stable to 5000C. Tungsten bronzes and other tungsten compounds are used in paints.