Refractory Metal Mo-41Re
ASTM B387 Grade 366
Rhenium addition dramatically improves low-temperature ductility and weldability of molybdenum, enabling use in thermocouples, X-ray targets, and aerospace thermal components where formability at room temperature is critical.
Reference datasheet — Mo-41Re 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.
Values for the SR condition
Mo-41Re tempers and conditions
Mo-41Re is supplied in 4 conditions, soft to hard. SR is the default FabDigit quotes; the values on this page are for it.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Arc-cast / EB-melted ingot and forged bar | Use for large forged or machined blanks and high-purity, low-interstitial stock; coarser grain and lower as-cast strength than wrought PM product. | 480 | 780 | 18 | 21 HRC | 6.3 % IACS |
Recrystallized | Pick when maximum ductility and deep-forming/welding capability are needed, or where service temperature will recrystallize the part anyway. | 520 | 850 | 25 | 22 HRC | — |
SRDefault Stress relieved | Standard stocked condition for sheet, rod and thermocouple wire — good strength with useful room-temperature ductility and dimensional stability. | 900 | 1,100 | 15 | 33 HRC | — |
Cold worked | Highest strength condition for springs, fine wire and thin foil where maximum stiffness-per-section and strength matter more than ductility. | 1,300 | 1,450 | 8 | 42 HRC | — |
What is Mo-41Re?
Rhenium addition dramatically improves low-temperature ductility and weldability of molybdenum, enabling use in thermocouples, X-ray targets, and aerospace thermal components where formability at room temperature is critical. Mo-41Re has a density of 13.6 g/cm³ (0.491 lb/in³), heavier than 81% of refractory metal grades. It melts at 2,500°C (4,532 °F). Mo-41Re has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of refractory metal grades. Elongation at break is 15% and the elastic modulus is 360 GPa (52.2 Msi).
What is Mo-41Re used for?
- Type C thermocouple wire
- X-ray tube targets
- Rocket nozzle liners
- Precision springs/foils
Advantages
- High strength — 900 MPa (131 ksi), better than 91% of refractory metal grades
- Stiff — 360 GPa (52.2 Msi), better than 91% of refractory metal grades
- High service temperature — 1,300°C (2,372 °F), better than 76% of refractory metal grades
Limitations
- Heavy — 13.6 g/cm³ (0.491 lb/in³), worse than 81% of refractory metal grades
Mo-41Re properties
Typical room-temperature values for Mo-41Re-SR; bars are the position among refractory metal grades.
Physical3
Mo-41Re has a density of 13.6 g/cm³ (0.491 lb/in³), heavier than 81% of refractory metal grades. It melts at 2,500°C (4,532 °F).
Mechanical13
Mo-41Re has a yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of refractory metal grades. Elongation at break is 15% and the elastic modulus is 360 GPa (52.2 Msi).
Thermal6
Mo-41Re is rated for continuous service to 1,300°C (2,372 °F). It conducts heat at 45 W/m·K (26 BTU/hr·ft·°F), better than 56% of refractory metal grades. Thermal expansion is 5.8 µm/m·K (3.22 µin/in·°F).
Electrical3
Mo-41Re conducts electricity at 6.2 % IACS, better than 51% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is good (58/100), worse than 66% of refractory metal grades.
Sustainability3
Producing a kilogram of Mo-41Re takes about 900 MJ of energy and emits 60 kg of CO₂ — less than 59% of refractory metal grades. Typical recycled content is 40%.
Manufacturability7
Mo-41Re's machinability is poor (22/100, worse than 73% of refractory metal grades); weldability very good (70/100); formability good (60/100).
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 refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. Mo-41Re is highlighted; hover a dot for its name, or open the interactive family chart.
Working with Mo-41Re
Is Mo-41Re easy to machine?
Tough and work-hardening — use sharp, positive-rake carbide or ground HSS, rigid setups, low speed with heavy positive feed and flood coolant; grinding and EDM are common for finish features.
Can Mo-41Re be welded?
Weldable by EB or GTAW in high vacuum or high-purity argon; unlike pure Mo the welds retain room-temperature ductility, but interstitial pickup (O, N, C) must be avoided.
Can Mo-41Re be formed, bent or molded?
Cold rollable to thin foil and drawable to fine wire with intermediate vacuum anneals; warm forming at 200–600 °C eases severe bends in heavy section.
Mo-41Re 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 |
|---|---|---|
| Reat the practical solubility limit before sigma/chi embrittlement | 39.5 – 42.5 | 41 |
| C | ≤ 0.01 | 0.01 |
| O | ≤ 0.01 | 0 |
| N | ≤ 0 | 0 |
| Fe | ≤ 0.01 | |
| Ni | ≤ 0.01 | |
| Si | ≤ 0.01 | |
| Mo | balance |
What surface finishes work on Mo-41Re?
Chemically or electropolished to bright finish; not anodizable — use Si-Cr-Fe pack cementation, iridium or CVD coatings for any oxidizing high-temperature exposure.
Equivalent designations
Standards and trade names that resolve to Refractory Metal Mo-41Re in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B387 Grade 366
- Similar grades
- R03640B387
How much does Mo-41Re cost?
Mo-41Re is a high-cost refractory metal ($$$$), 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.
Mo-41Re — frequently asked
What is Mo-41Re used for?
Mo-41Re is typically used for type C thermocouple wire, X-ray tube targets, rocket nozzle liners and precision springs/foils. In short: ductile, weldable molybdenum; type C thermocouple alloy; costliest Mo alloy.
What is the yield strength of Mo-41Re?
Mo-41Re has a typical yield strength of 900 MPa (131 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 91% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Mo-41Re easy to machine?
Not especially — machinability is rated poor (22/100, worse than 73% of refractory metal grades). Tough and work-hardening — use sharp, positive-rake carbide or ground HSS, rigid setups, low speed with heavy positive feed and flood coolant; grinding and EDM are common for finish features.
Can Mo-41Re be welded?
Yes — weldability is rated very good (70/100). Weldable by EB or GTAW in high vacuum or high-purity argon; unlike pure Mo the welds retain room-temperature ductility, but interstitial pickup (O, N, C) must be avoided.
What surface finishes work on Mo-41Re?
Chemically or electropolished to bright finish; not anodizable — use Si-Cr-Fe pack cementation, iridium or CVD coatings for any oxidizing high-temperature exposure.
Can Mo-41Re be formed, bent or molded?
Cold rollable to thin foil and drawable to fine wire with intermediate vacuum anneals; warm forming at 200–600 °C eases severe bends in heavy section.
What is the maximum service temperature of Mo-41Re?
Mo-41Re is rated for continuous use to about 1,300°C (2,372 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Mo-41Re-SR and Mo-41Re-CW?
SR is the default condition — standard stocked condition for sheet, rod and thermocouple wire — good strength with useful room-temperature ductility and dimensional stability. CW: highest strength condition for springs, fine wire and thin foil where maximum stiffness-per-section and strength matter more than ductility. Yield strength is 900 MPa in SR versus 1,300 MPa in CW.
How much does Mo-41Re cost?
Mo-41Re is a high-cost refractory metal ($$$$), 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 B387 — Molybdenum and Molybdenum Alloy Bar, Rod, and Wire — ASTM International (2018)
- Molybdenum-Rhenium Alloy (Mo-41Re, Mo-47.5Re) technical data — Rhenium Alloys, Inc. (2022)
- Molybdenum alloys — material properties — Plansee SE (2023)
- 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 (Mo-Re system) — ASM International (1992)
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.