(Chemical symbol: W). A very hard steel-gray metal which melts at a temperature of approximately 3400°C (6150°F), the highest melting point of all metals. Tungsten is used in the pure state and also in alloys for electrodes for resistance welding and arc welding. Its tensile strength when drawn into wire is approximately 3448 MPa (500 000 psi). As an alloying element in tool steel, tungsten tends to produce a fine, dense grain when used in relatively small quantities. When used in larger quantities, from 17 to 20%, and in combination with other alloys, it produces a steel that retains its hardness at high temperatures.
Tungsten is also used in certain heat resistant steels in which the retention of strength at high temperatures is important. This element is usually used in combination with chromium or other alloying agents.