MOLYBDENUM TUBE / PIPE
Molybdenum tube and sleeve
OD 10–200mm | Wall 1–10mm | Mo ≥99.95% | Turned / ground / welded
WeiBeam · Electrode solutions for high-temperature melting
Molybdenum tubes are made from high-purity molybdenum by sintering, forging or roll-welding sheet, and are also called molybdenum sleeves or protection tubes. Common sizes are OD 10–200mm with a 1–10mm wall, with length matched to the assembly. Compared with a solid rod, a tube carries a higher section modulus at the same weight, which suits supports, isolation and protection structures at high temperature.
Start selection with temperature and atmosphere: pure molybdenum is stable in vacuum or reducing conditions, while in oxidizing atmospheres the service temperature must be limited or the surface protected. Then fix the inner and outer diameter, wall and concentricity; for thermocouple protection tubes, also agree wall uniformity and end sealing.
In high-temperature melting and thermal-field systems this part is often used alongside electrodes elsewhere in the line. We recommend selecting them together against furnace structure, assembly method and working temperature to reduce thermal-expansion mismatch between different materials.
FEATURES
Molybdenum tube — key features
Core characteristics for furnace conditions and operating requirements.
Wide size range
OD 10–200mm and wall 1–10mm, with length made to drawing.
Grade options
Mo1 as standard; MoLa and TZM can be assessed for the duty.
Machining
Turning, grinding, drilling and roll welding, with stepped or sealed ends.
Inspection
Dimensions, wall, concentricity and surface accepted to drawing with a mill certificate.
SPECIFICATIONS
Specification data
This product is accepted to the relevant material standard or a mutual technical agreement, with key dimensions, density and material inspected batch by batch. Special sizes can be machined to drawing.
| Parameter | Specification |
|---|---|
| Form | Seamless tube / roll-welded tube / sleeve |
| Outer diameter | Typically OD 10–200mm, custom to drawing |
| Wall thickness | Typically 1–10mm |
| Length | Made to assembly size, usually ≤600mm |
| Grades | Mo1 / MoLa / TZM (assessed for duty) |
| Molybdenum content | ≥99.95% |
| Density | ≥10.15 g/cm³ |
| Surface | Turned / ground / alkali-cleaned |
| Typical uses | Thermocouple protection, high-temperature supports, vacuum furnace structures, glass-melting fixtures |
Material and physical properties
| Parameter | Typical value / note |
|---|---|
| Available grades | Mo1 (pure Mo) / MoLa (lanthanum-doped) / TZM (Ti-Zr-Mo) / Mo-Zr ODS |
| Molybdenum content | ≥99.95% (higher purity by technical agreement) |
| Density | ≥10.2 g/cm³ (varies slightly by grade and condition) |
| Melting point | ≈2620–2623 °C |
| Resistivity (20 °C) | ≈0.053 µΩ·m |
| Conductivity | ≥30% IACS |
| Thermal expansion | ≈5.25×10⁻⁶/°C |
| Elastic modulus | ≈315 GPa |
| Hardness | ≥85 HRB (by grade and condition) |
| Standards | Accepted to the relevant material standard or a mutual technical agreement |
| Factory inspection | Spectral composition, density, metallography, ultrasonic inspection, dimensions and appearance |
| Delivery documents | Mill certificate with full batch traceability |
Typical values for pure molybdenum. MoLa, TZM and special sizes follow the mutual technical agreement and the test report supplied with each batch.
FAQ
Common questions
Selection, customization and quotation questions.
Are molybdenum tube and sleeve different products?
They usually refer to the same family; a sleeve emphasizes a fitting or protection role. Specifying inner diameter, outer diameter, wall, length and tolerance is more precise than choosing a name.
Can molybdenum tubes be roll-welded?
Yes. Roll welding suits larger diameters and shorter runs; weld quality and soundness are inspected by agreement. Small diameters with tight concentricity are usually turned from sintered or forged tube stock.
What matters for a thermocouple protection tube?
Agree wall uniformity, concentricity and end sealing. In oxidizing atmospheres assess the upper service temperature and shorten the replacement interval if needed.
CUSTOM
Selection and quotation
Share your furnace structure and process conditions. Our engineers will help select the right electrode and you can request a standard-size sample. We support export customers worldwide with remote technical coordination.