Tungsten Product ASTM B760-2007, GB/T 3875-2006 Standard 99.95% min
Tungsten Ground Tube
1.Tungsten tube features.
Tungsten metal is lustrous and silvery white in colour, and does
not occur naturally (it has an abundance of 1 ppm in the earth's
crust).
It is found in the ore Wolframite, a tungstate of iron and
manganese, (FeMn)WO4, which is converted to the trioxide and then
reduced to the metal by reduction in hydrogen (carbon cannot be
used as the very stable carbide would result).
Tungsten metal is relatively inert, resisting attack by oxygen,
acids and alkalis, although it will react with fused, oxidising
alkali media.
It has the highest melting point of all metals and, when pure, it
can be worked with relative ease; however, the presence of
impurities renders tungsten extremely brittle and, therefore,
difficult to fabricate.
The high melting point of tungsten makes it suitable for use as
electric filaments (e.g. in electric light bulbs).
It is also the basis of a range of alloys containing tungsten,
copper and nickel which are used for radiation shielding as they
provide a 50% increase in density compared to lead.
Tungsten and its alloys also find uses in military applications
(e.g. armour and shells), as well as counter-balance materials.
Tungsten carbide powder (with possible additions of titanium and
tantalum carbides) along with nickel or cobalt powders, are
compressed and sintered to produce cemented carbides.
These products are used in place of high speed steel to form the
tip of cutting and drilling tools, or for parts which will be
subjected to heavy useage.
Tungsten tube has 99.95% purity and 19.3g/cm3 density .
Suitable for rare earth industry and the electronics industry.
2.Tungsten tube tolerance
Polished tungsten tube tolerance
| Diameter | Diameter Tolerance | Length | tolerance | Length | Tolerance |
| 2~6 | +/- 0.03 | 20<L<200 | 0 , +0.5 | >=200 | 0 , +1 |
| 7~30 | +/- 0.05 | 20<L<200 | 0 , +0.5 | >=200 | 0 , +1 |
| >30 | +/- 0.1 | >=200 | 0 , +1 | | |
Black surface tungsten tube tolerance
| Diameter | Diameter tolerance | Length Tolerance |
| 2~15 | 0 , +0.2 | 0 , +1 |
| 16~40 | 0 , +0.3 | 0 , +1 |
| >40 | 0 , +0.5 | 0 , +1 |
