The U-shaped EB tungsten filament is a high-purity tungsten wire heating element bent into a U shape, widely used in electron beam evaporation coating equipment.

Cleaned Tungsten Wire, also known as white tungsten wire, does not refer to tungsten wire with a white surface, but refers to tungsten wire that has been electrolytically washed and polished. The surface of this tungsten wire is smooth and clean, without graphite emulsion attached, and presents a silver-gray metallic luster.

Thorium tungsten rod is a tungsten alloy bar containing 2% thorium oxide, known for its excellent high-temperature strength, resistance to electron emission, and thermal stability. 

The black surface of black tungsten wire is mainly because graphite emulsion is sprayed during the drawing process. As a lubricant, graphite emulsion can effectively reduce the friction coefficient between the tungsten wire and the drawing die, reduce the risk of tungsten wire breakage during the drawing process, and extend the service life of the drawing die. After the graphite emulsion adheres to the surface of the tungsten wire, a thin black coating will be formed, which is also the source of the appearance characteristics of black tungsten wire. The graphite layer can be removed by alkaline washing.