HCT Molybdenum Wire
Elmet is a leading global provider of high-quality potassium doped molybdenum (HCT) wire products and the only US owned and operated producer. All our wire products are manufactured in Lewiston, Maine USA. Elmet has a 90-year legacy dating back to our history as part of Royal Philips where we manufactured wire and lighting filaments for Philips Lighting. We manufacture and stock common sizes of our molybdenum, molybdenum potassium doped HCT wire and tungsten wires. Elmet manufactures wire as small as 7/10,000ths of an inch (0.0007″). Wire is typically sold on a per km basis (fine wire) and a kg basis (heavy wire).
Molybdenum Wire Types
Elmet produces four types of molybdenum wire – Pure, HCT (potassium-silicate doped), MoLa (lanthanum oxide doped), and MB (molybdenum-tungsten alloy—various compositions). Diameter sizes range from less than 0.001 inches to 0.187 inches.
- Pure molybdenum – used in standard applications for the production of mandrels, supports, furnace elements, furnace windings and formed parts.
- HCT (potassium doped) molybdenum
- MoLa (lanthanum oxide doped) molybdenum
- MB (molybdenum-tungsten alloy—various compositions)
HCT and MoLa Wire
HCT and MoLa are doped products that have higher recrystallization temperatures. For diameters below 0.090 inches, they exhibit better ductility after recrystallization. These products are used in more demanding applications, such as halogen lamp leads, to provide superior weld ability and glass-to-metal seal properties. Application temperature limits for MoLa exceed those of HCT, and MoLa finds applications where the limits of HCT are reached.
Molybdenum Tungsten Alloy Wire
MB is an alloyed product of molybdenum with tungsten (typically 50:50, with others available upon request). It combines the properties of tungsten and molybdenum to offer blended properties with unique resistance and oxide color capabilities that find applications in automotive and aircraft windshield heating (defrosting).
Dimensions and Tolerances
Wire diameters are generally expressed in terms of inches or mils (thousandths of an inch). For thin wires from 0.001 inches to 0.020 inches, the size of the wire is measured by weight per unit length. That is, the weight expressed as milligrams of a 200mm length of wire. The standard diameter tolerance is ± 3% of the weight measurement. For mandrel applications, the tolerance is normally ± 1%.
Tensile Strength
Tensile strength for molybdenum wire is usually expressed in grams per milligram weight of a 200-millimeter length (or) g/mg/200 mm. The normal range of values is 40 to 60 grams. In general, as tensile strength increases, wire straightness decreases.
Straightness
The measure of the straightness of a metal 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 the straightness increases, tensile strength decreases.
Out of Roundness
Out of roundness of wire does not exceed 4% of the wire diameter. It is measured as follows:
Out of Roundness = (Max Diameter – Min Diameter) / Max Diameter x 100
Quality and Finish
Wire is free of scratches, kinks, and distortions insofar as they are harmful to the intended use of the product. The 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 Electro-chemical etching.
Spooling
Wire is spooled on clean, defect-free spools. For very large diameters, wire is self-coiled. Spools are level filled without piling near flanges. Elmet ensures the outer end of the wire is properly marked and attached securely to the spool or self-coil.
Pure Molybdenum Wire
| Typical Application | Description | Available Diameters | Tolerances |
| Support Wire | Cleaned | .003″ to .020″ | ± 3% wt |
| Support Wire | Cleaned | .020″ to .050 “ | ± 1.5% dia |
| Redraw Wire | Black | .001″ to .020″ | ± 3% wt |
| Redraw Wire | Black | .020″ to .060″ | ± 1.5% dia |
| Heating Elements | Cleaned | .001″ to .020″ | ± 3% wt |
| Heating Elements | Cleaned | .020″ to .250″ | ± 1.5% dia |
| Mandrel Wire | Cleaned | .004″ to .020″ | ± 1% to 3% wt |
HCT and MoLa Molybdenum Wire
| Typical Application | Description | Available Diameters | Tolerances |
| Halogen Leads | Cleaned | .010″ to .035″ | ± 3% wt |
| Support Wire | Cleaned | .003″ to .030″ | ± 3% wt |
| Heating Elements | Cleaned | .001″ to .020″ | ± 3% wt |
| Heating Elements | Cleaned | .020″ to .250″ | ± 1.5% dia |
MB (Molybdenum-Tungsten Alloyed) Wire
| Typical Application | Description | Available Diameters | Tolerances |
| Aircraft and Automotive
Windshield Defrosting |
Special
oxidized |
<.001″ to .003″
(also can be ordered by Wire resistance) |
± 3% wt |
| Other Varied applications | Cleaned | .003″ to .030″ | ± 3% wt |
Resources:
HCT Molybdenum Products Data Sheet 2017
Lanthanated Molybdenum Plate 2017
Molybdenum Physical-Mechanical Properties 2017