Tungsten Rods for Heater:

Tungsten rod surface condition: Forged surface and polished surface, Tungsten rod with polished surface has better diameter homogeneity than tungsten rods with forged surface, which will make the electrical resistivity in the length direction more uniform. Diameter tolerance: forged surface ± 0.1mm, polished surface ± 0.05mm. The bending radius and shape of the tungsten rods could be accurately manufactured according to the customers’ drawings and specifications.

Physical & Chemical Properties:

Diameter	Purity	Density	Usage Temperature	Vapor	Blackness	Coefficient of Thermal Expansion	Recrystallization Temperature
3-10mm	≥99.95%	≥19.2g/cm3	<2500℃	10-6Pa	0.295	4.98x10-6	~1350℃

The Electrical Resistivities of Tungsten Bars at Different Temperature(Ω.mm2/m)

Temperature（℃）	0	1000	1500	1800	1900	2000	2100	2200
Electrical resistivity： (Ω.mm2/m)	0.05	0.326	0.486	0.594	0.630	0.671	0.716	0.761

Parameters of Copper Electrodes::

Quality Control:

- Composition analysis, particle size distribution are tested for each batch of tungsten powder before putting into production.

- Tungsten rods are subject to strict surface inspection and eddy current flaw inspection before the next bending stage.

- Before Tungsten heaters are packaged and delivered,they must be 100% checked, Products will not passed if not meet the requirements.

Storage & Usage Recommendations:

- Tungsten heaters are brittle and must be handled gently with care.

-  Tungsten heaters must be stored in a dry area  (humidity less than 60%), otherwise it is easy to be oxidized.

- After first usage, tungsten heaters are more brittle after recrystallation and please be careful not to touch them. 

- Because of the recrystallation issue, ceriated tungsten , lanthanated tungsten and tungsten doped with potassium are recommended if possible for better performance and prolonged service life.