Tungsten Alloy W-25Re
UNS R05400 · ASTM B387 Grade WRe25 · also W-Re Alloy
W-25Re is tungsten alloyed with 25% rhenium (UNS R05400, ASTM B760 and B387 Grade WRe25), where rhenium lowers the ductile-to-brittle transition and stabilises thermoelectric output.
Reference datasheet — W-25Re is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
W-25Re tempers and conditions
W-25Re is supplied in one standard condition, PM-Sintered.
Supply forms, finishes and certifications
Ways W-25Re is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
CR-Sheet | Cold-rolled sheet / strip / foil | Supply form |
CW-WireDefault | Cold-drawn wire | Supply form |
Rx-Sheet | Recrystallized (annealed) sheet / strip | Supply form |
Rx-Wire | Recrystallized (annealed) wire / rod | Supply form |
SR-Wire | Stress-relieved / straightened wire | Supply form |
Swaged-Rod | Sintered + swaged rod / bar | Supply form |
What is W-25Re?
W-25Re is tungsten alloyed with 25% rhenium (UNS R05400, ASTM B760 and B387 Grade WRe25), where rhenium lowers the ductile-to-brittle transition and stabilises thermoelectric output. It is the standard leg for Type C and Type D thermocouples and is supplied as cold-drawn, stress-relieved and recrystallised wire, swaged rod, sheet and PM-sintered shapes, with 1850 MPa yield, 2100 MPa tensile, 4% elongation and use to 2400 °C in vacuum or inert atmosphere. It welds and forms better than pure tungsten (formability 30) but machinability rates 8, rhenium content makes it costly, and any air exposure above roughly 500 °C requires a protective coating. W-25Re has a density of 19.7 g/cm³ (0.712 lb/in³), heavier than 98% of tungsten alloy grades. It melts at 3,000°C (5,432 °F). W-25Re has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 94% of tungsten alloy grades. Elongation at break is 4% and the elastic modulus is 400 GPa (58 Msi).
What is W-25Re used for?
- Type C/D thermocouple wire
- High-temperature furnace parts
- Electron tube components
- Aerospace nozzle inserts
Advantages
- Readily welded — 45/100, better than 100% of tungsten alloy grades
- Forms and bends easily — 30/100, better than 98% of tungsten alloy grades
- High strength — 1,850 MPa (268 ksi), better than 94% of tungsten alloy grades
- High service temperature — 2,400°C (4,352 °F), better than 86% of tungsten alloy grades
- Ductile — tolerates forming and impact — 4%, better than 80% of tungsten alloy grades
Limitations
- Poor heat conductor — 45 W/m·K (26 BTU/hr·ft·°F), worse than 100% of tungsten alloy grades
- High embodied carbon — 55 kg CO₂/kg, worse than 100% of tungsten alloy grades
- Low electrical conductivity — 5.7 % IACS, worse than 95% of tungsten alloy grades
W-25Re properties
Typical room-temperature values; bars are the position among tungsten alloy grades.
Physical3
W-25Re has a density of 19.7 g/cm³ (0.712 lb/in³), heavier than 98% of tungsten alloy grades. It melts at 3,000°C (5,432 °F).
Mechanical11
W-25Re has a yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 94% of tungsten alloy grades. Elongation at break is 4% and the elastic modulus is 400 GPa (58 Msi).
Thermal6
W-25Re is rated for continuous service to 2,400°C (4,352 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), worse than 100% of tungsten alloy grades. Thermal expansion is 4.6 µm/m·K (2.56 µin/in·°F).
Electrical3
W-25Re conducts electricity at 5.7 % IACS, worse than 95% of tungsten alloy grades.
Chemical & Environmental3
Corrosion resistance is good (60/100), better than 50% of tungsten alloy grades.
Sustainability4
Producing a kilogram of W-25Re takes about 750 MJ of energy and emits 55 kg of CO₂ — more than 100% of tungsten alloy grades. Typical recycled content is 25%.
Manufacturability7
W-25Re's machinability is not recommended (8/100, worse than 71% of tungsten alloy grades); weldability fair (45/100); formability poor (30/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the tungsten alloy family
Yield strength against density for every tungsten alloy grade FabDigit runs. W-25Re is highlighted; hover a dot for its name, or open the interactive family chart.
Working with W-25Re
Is W-25Re easy to machine?
Treat as a grinding/EDM material — carbide or PCD tooling at low speed with rigid setups; conventional turning/milling causes chipping and rapid tool wear, so near-net PM or wire-EDM is preferred.
Can W-25Re be welded?
Rhenium ductilizes the weld, so GTAW/EB/laser and resistance butt welding in high-purity argon or vacuum are practical; keep oxygen/carbon pickup to a minimum and avoid post-weld cold bending of coarse-grained welds.
Can W-25Re be formed, bent or molded?
Cold drawing of fine wire is possible; sheet and rod should be warm-worked at 300–1200 °C, and bend radii below ~5t in the cold-worked condition risk cracking.
W-25Re chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| Resolid-solution ductilizer; nominal 25 wt% | 24 – 26 | 25 |
| Cmax, typical high-purity wire | ≤ 0.01 | 0 |
| O | ≤ 0.01 | 0 |
| Fe | ≤ 0.01 | 0 |
| Mo | ≤ 0.02 | 0.01 |
| Ni | ≤ 0.01 | 0 |
| Si | ≤ 0.01 | 0 |
| W | balance |
What surface finishes work on W-25Re?
Electropolishing or chemical cleaning in alkaline/peroxide solutions gives bright surfaces; for air service above ~500 °C a silicide, iridium or CVD coating is mandatory, otherwise use vacuum/inert atmospheres.
Equivalent designations
Standards and trade names that resolve to Tungsten Alloy W-25Re in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R05400
- ASTM
- B387 Grade WRe25
- Trade names
- W-Re Alloy
- Also called
- W25Re
- Similar grades
- B760
How much does W-25Re cost?
W-25Re is a high-cost tungsten alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
W-25Re — frequently asked
What is W-25Re used for?
W-25Re is typically used for type C/D thermocouple wire, high-temperature furnace parts, electron tube components and aerospace nozzle inserts. In short: ductile tungsten alloy; type C thermocouple standard; service to 2400 °C.
What is the yield strength of W-25Re?
W-25Re has a typical yield strength of 1,850 MPa (268 ksi) and a tensile strength of 2,100 MPa (305 ksi) — stronger than 94% of tungsten alloy grades.
Is W-25Re easy to machine?
Not especially — machinability is rated not recommended (8/100, worse than 71% of tungsten alloy grades). Treat as a grinding/EDM material — carbide or PCD tooling at low speed with rigid setups; conventional turning/milling causes chipping and rapid tool wear, so near-net PM or wire-EDM is preferred.
Can W-25Re be welded?
With care — weldability is rated fair (45/100). Rhenium ductilizes the weld, so GTAW/EB/laser and resistance butt welding in high-purity argon or vacuum are practical; keep oxygen/carbon pickup to a minimum and avoid post-weld cold bending of coarse-grained welds.
What surface finishes work on W-25Re?
Electropolishing or chemical cleaning in alkaline/peroxide solutions gives bright surfaces; for air service above ~500 °C a silicide, iridium or CVD coating is mandatory, otherwise use vacuum/inert atmospheres.
Can W-25Re be formed, bent or molded?
Cold drawing of fine wire is possible; sheet and rod should be warm-worked at 300–1200 °C, and bend radii below ~5t in the cold-worked condition risk cracking.
What is the maximum service temperature of W-25Re?
W-25Re is rated for continuous use to about 2,400°C (4,352 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
How much does W-25Re cost?
W-25Re is a high-cost tungsten alloy ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASTM B760 — Tungsten Plate, Sheet and Foil — ASTM International (2021)
- ASTM B387 — Molybdenum and Molybdenum Alloy Bar, Rod and Wire (analogous refractory-metal product forms) — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Refractory Metals) — ASM International (1990)
- ASM Handbook Vol. 3 — Alloy Phase Diagrams (W–Re system) — ASM International (1992)
- Tungsten–Rhenium Alloy Wire and Thermocouple Data — Rhenium Alloys, Inc. / Plansee (2023)
- ASTM E230 / IEC 60584 thermocouple reference data (Type C/D W-Re pairs) — ASTM / IEC (2020)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.