Tungsten is a chemical element with atomic number 74 and W is the chemical symbol of it which stands for wolfram. The name of "tungsten" means "heavy stone" in some countries .Tungsten is much harder than Gold and steel, otherwise, it is great cheaper than gold. It is a grayish-white lustrous metal in raw form and often brittle and hard to work, however, if it is in the form of pure, it can be worked easily. Pure tungsten is mainly used in electrical applications, while tungsten compounds and alloys are usually used in various applications such as in incandescent light bulb filaments, X-ray tubes, super alloys and so on.
The reason why it is used for incandescent light bulb filaments is that although tungsten is not as strong as any kind of other metals at normal temperatures, but once it get into very high temperatures, the others start melting or dropping dramatically while tungsten keeps up a relatively high strength as it is within high melting temperature about 3500 degrees c.