Fine tungsten wire
|Diameter, mm||Diameter telorance, %||Weight ( 200mm ), mg||Length min, m|
|0.35−0.7||±1.5−±2.5||-||same as 150g|
|0.7−1.8 ±||±1.0−±2.0||-||same as 200g|
Total impurity elements
We supply tungsten wire, tungsten bar, tungsten plate, tungsten
sheet, tungsten rod, tungsten electrode, tungsten fabricated parts,
tungsten alloy, tungsten copper alloy, tungsten heavy alloy. Please
contact with our sales department for more details.
We produces two types of tungsten wire - Pure and WAL (K-Al-Si
Pure tungsten wire is produced in sizes above. 020 inches in diameter. Typical usage
is for restraightening into rod products and for applications where
there is a low alkali content requirement.
WAL wire which has been doped with trace amounts of potassium, causing the
wire to exhibit an elongated interlocking grain structure with
non-sag properties after recrystallization. WAL wire is produced in
sizes from less than 0.02mm up to 6.5mm in diameter and is used
largely for lamp filament and wire filament applications.
Dimensions and Tolerances
Wire diameters are generally expressed in terms of mm(or inches).
For thin wires from 0.02mm up to 0.5mm in diameter, the diameter of
the wire is measured by weight per unit length. That is, the weight
expressed in mg of a 200 mm length of wire.
The standard diameter tolerance is 3% of the weight measurement.
Closer tolerances are available, depending upon the application for
the wire product.
For thicker wires from 0.5mm up to 6.5mm in diameter, the mm
measurements are used. The tolerances are expressed as a percentage
of the diameter. Standard tolerance is 1.5%.
Tensile strength for tungsten wire is usually expressed in grams
per milligram weight of a 200mm (or) g/mg/200mm. The normal range
of values is from 40 to 110 grams. In general, as tensile strength
increases, wire straightness decreases.
Wire may be finished in the unstraightened or as drawn condition
and is controlled to FOTMA's internal standards, In addition, wire
can be straightened via mechanical or heat treating processes.
Typically, the measure of the straightness of a tungsten wire is
obtained by cutting a ten inch long piece of wire and allowing it
to lie on a flat clean surface. The maximum deviation from a
straight line along its length is the quantitative measure of its
straightness. In general, as the degree of straightness increases,
tensile strength decreases.
Longitudinal cracks with a depth of more than 15% of the wire
diameter are called splits. The wire is checked for splits with an
eddy current split detector. The split level for a given length of
wire is typically less than 5%.
Quality and Finish
Wire is free of scratches, kinks and distortions insofar as they
are harmful to the intended end use of the product. Surface finish
is supplied in the black, as drawn condition, where drawing
lubricants and oxides are retained on the surface, or in the
cleaned condition by firing in hydrogen or electrochemical etching.
Wire is spooled on clean, defect free spools. For very large
diameters, tungsten wire is self coiled. Spools are level filled
without piling near flanges. The outer end of the wire is properly
marked and attached securely to the spool or self coil.