Tungsten wire is made from doped powders, that is, powders in which small quantities of Potassium, Silicon and Aluminium have been incorporated. Their purpose is to influence the recrystallized grain structure to reduce the creep rate at the high temperatures of incandescent filaments. The powders are consolidated under high pressure, sintered at high temperatures and worked by rolling and swaging to heavy rod suitable for drawing.
Tungsten rod is produced by pressing and sintering into billets, which are worked by rolling or swaging into rod. smaller sizes are produced by subsequent drawing. Tungsten rod is produced in straight random lengths with a smooth swaged surface at diameters 3mm and larger, and with a smooth drawn finish below 3mm. A centerless-ground finish can also be furnished . Specific lengths and special fabrications can be supplied upon request.
Tungsten heater formed from 9mm Dia rod