Dimensions and Tolerances of Tungsten Wire
Tungsten wires’ diameters are generally expressed in inches or mils (thousandths of an inch). For thin wires from .001 inches up to .020 inches in diameter, the wire's diameter 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.
Straightness of Tungsten Wire
The wire may be finished in the unstraightened or as the drawn condition. The wire can also 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.
Quality and Finish of Tungsten Wire
The wire is free of scratches, kinks, and distortions because they are harmful to the product's intended end-use. 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.
Tungsten Wire Spooling
The wire is free of scratches, kinks, and distortions because they are harmful to the product's intended end-use. 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.
Tungsten Wire Specifications
|
Diameter (um) |
Length (m) |
Tolerance Weight (mg/200mm) |
Tolerance Dia. (mm) |
|
10<d<=18 |
>0.30-1 |
— |
±3 |
±4 |
— |
— |
|
18<d<=40 |
>1-5 |
±2 |
±2.5 |
±3 |
— |
— |
|
40<d<=80 |
>5-19 |
±1.5 |
±2.0 |
±2.5 |
— |
— |
|
80<d<=150 |
>19-68 |
±1.0 |
±1.5 |
±2.0 |
— |
— |
|
150<d<=300 |
>68-273 |
±1.0 |
±1.5 |
±2.0 |
— |
— |
|
300<d<=350 |
>273-372 |
— |
±1.0 |
±1.5 |
— |
— |
|
350<d<=500 |
— |
|
|
|
±1.5 |
±2.0 |
|
500<d<=1800 |
— |
|
|
|
±1.0 |
±1.5 |
