Refractory Metal R04261
UNS R04261 · ASTM B393 Type 4
R04261 is the commercial-grade Nb-1Zr alloy to ASTM B393 Type 4, offering the zirconium strengthening of the reactor grade without its strict interstitial control, and is stocked annealed, stress-relieved, cold-worked, hot-worked and as electron-beam ingot.
Reference datasheet — R04261 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 Annealed condition
R04261 tempers and conditions
R04261 is supplied in 4 conditions, soft to hard. Annealed 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 |
|---|---|---|---|---|---|---|
AnnealedDefault vacuum recrystallization annealed (ASTM B393/B392 annealed condition) | Standard stocked condition for sheet, plate, bar and tube — maximum ductility for forming, welding and deep drawing. | 200 | 310 | 25 | 105 HB | 41 W/m·K |
Hot worked / as-forged bar and billet | Mill condition for heavy bar, forgings and machining stock where a final anneal is not required. | 260 | 380 | 20 | 124 HB | 8.4 % IACS |
Stress relieved | Choose when moderate strength must be combined with dimensional stability after cold forming or machining. | 340 | 420 | 15 | 143 HB | 8.4 % IACS |
Cold worked | Highest room-temperature strength and hardness for wire, thin strip and springs, but limited formability and it recrystallizes above ~1100 °C. | 500 | 560 | 8 | 185 HB | — |
Supply forms, finishes and certifications
Ways R04261 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
EB-Ingot | Electron-beam / vacuum-arc melted ingot | Supply form |
What is R04261?
R04261 is the commercial-grade Nb-1Zr alloy to ASTM B393 Type 4, offering the zirconium strengthening of the reactor grade without its strict interstitial control, and is stocked annealed, stress-relieved, cold-worked, hot-worked and as electron-beam ingot. It combines about 200 MPa yield, 310 MPa tensile, 25% elongation, 105 HB (60 HRB) and 41 W/m·K thermal conductivity with service to roughly 1200 °C in vacuum or inert gas, plus near-full cold formability and very good weldability. In air it oxidises and must be aluminide- or silicide-coated above about 400 °C; use reactor-grade R04251 where interstitial limits are specified. R04261 has a density of 8.57 g/cm³ (0.31 lb/in³), heavier than 51% of refractory metal grades. It melts at 2,410°C (4,370 °F). R04261 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 87% of refractory metal grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
What is R04261 used for?
- Rocket nozzle liners
- High-temperature furnace parts
- Chemical process equipment
- Vacuum tube components
Advantages
- Readily welded — 90/100, better than 100% of refractory metal grades
- Forms and bends easily — 92/100, better than 95% of refractory metal grades
Limitations
- Low strength — 200 MPa (29 ksi), worse than 87% of refractory metal grades
R04261 properties
Typical room-temperature values for R04261-Annealed; bars are the position among refractory metal grades.
Physical3
R04261 has a density of 8.57 g/cm³ (0.31 lb/in³), heavier than 51% of refractory metal grades. It melts at 2,410°C (4,370 °F).
Mechanical13
R04261 has a yield strength of 200 MPa (29 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 87% of refractory metal grades. Elongation at break is 25% and the elastic modulus is 103 GPa (14.9 Msi).
Thermal6
R04261 is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 41 W/m·K (23.7 BTU/hr·ft·°F), worse than 53% of refractory metal grades. Thermal expansion is 7.1 µm/m·K (3.94 µin/in·°F).
Electrical3
R04261 conducts electricity at 8.6 % IACS, better than 58% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), better than 52% of refractory metal grades.
Sustainability4
Producing a kilogram of R04261 takes about 1,100 MJ of energy and emits 65 kg of CO₂ — less than 54% of refractory metal grades. Typical recycled content is 25%.
Manufacturability7
R04261's machinability is poor (33/100, better than 71% of refractory metal grades); weldability excellent (90/100); formability excellent (92/100).
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. R04261 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with R04261
Is R04261 easy to machine?
Gummy and galling-prone: use sharp high-positive-rake carbide or HSS tools, slow-to-moderate speeds, heavy feeds, chlorinated or flood coolant, and never let the tool dwell; degrease thoroughly before any high-temperature use.
Can R04261 be welded?
Excellent GTAW/EBW/laser weldability but only under high-purity argon trailing shield, glove box or vacuum — any O/N/H pickup above ~500 °C embrittles the weld; no filler needed for thin sections and no post-weld heat treatment other than vacuum stress relief.
Can R04261 be formed, bent or molded?
Very ductile cold: deep draws, spins, bends to tight radii at room temperature with lubricated tooling (avoid iron pickup); anneal 1100–1250 °C in vacuum between heavy reductions.
R04261 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 |
|---|---|---|
| Zralloying addition; scavenges oxygen | 0.8 – 1.2 | 1 |
| C | ≤ 0.01 | |
| Omax; looser than reactor grade R04251 | ≤ 0.03 | |
| N | ≤ 0.01 | |
| H | ≤ 0 | |
| Fe | ≤ 0.01 | |
| Ta | ≤ 0.1 | |
| W | ≤ 0.05 | |
| Mo | ≤ 0.02 | |
| Hf | ≤ 0.02 | |
| Ti | ≤ 0.03 | |
| Si | ≤ 0.01 | |
| Ni | ≤ 0.01 | |
| Nbbalance; commercial grade per ASTM B391/B392/B393/B394 Type 4 | balance |
What surface finishes work on R04261?
Pickle in HNO3/HF mixtures to remove oxide (short exposure — HF attacks Nb), electropolish for high-purity or UHV surfaces, or anodise to a coloured Nb2O5 film; for service in air above ~400 °C an aluminide or silicide coating is mandatory.
Equivalent designations
Standards and trade names that resolve to Refractory Metal R04261 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B393 Type 4
- Also called
- Nb-1Zr
How much does R04261 cost?
R04261 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.
R04261 — frequently asked
What is R04261 used for?
R04261 is typically used for rocket nozzle liners, high-temperature furnace parts, chemical process equipment and vacuum tube components. In short: commercial Nb-1Zr workhorse; weldable and highly formable; hot service to 1200 °C.
What is the yield strength of R04261?
R04261 has a typical yield strength of 200 MPa (29 ksi) and a tensile strength of 310 MPa (45 ksi) — weaker than 87% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is R04261 easy to machine?
Not especially — machinability is rated poor (33/100, better than 71% of refractory metal grades). Gummy and galling-prone: use sharp high-positive-rake carbide or HSS tools, slow-to-moderate speeds, heavy feeds, chlorinated or flood coolant, and never let the tool dwell; degrease thoroughly before any high-temperature use.
Can R04261 be welded?
Yes — weldability is rated excellent (90/100). Excellent GTAW/EBW/laser weldability but only under high-purity argon trailing shield, glove box or vacuum — any O/N/H pickup above ~500 °C embrittles the weld; no filler needed for thin sections and no post-weld heat treatment other than vacuum stress relief.
What surface finishes work on R04261?
Pickle in HNO3/HF mixtures to remove oxide (short exposure — HF attacks Nb), electropolish for high-purity or UHV surfaces, or anodise to a coloured Nb2O5 film; for service in air above ~400 °C an aluminide or silicide coating is mandatory.
Can R04261 be formed, bent or molded?
Very ductile cold: deep draws, spins, bends to tight radii at room temperature with lubricated tooling (avoid iron pickup); anneal 1100–1250 °C in vacuum between heavy reductions.
What is the maximum service temperature of R04261?
R04261 is rated for continuous use to about 1,200°C (2,192 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between R04261 Annealed and R04261-CW?
Annealed is the default condition — standard stocked condition for sheet, plate, bar and tube — maximum ductility for forming, welding and deep drawing. CW: highest room-temperature strength and hardness for wire, thin strip and springs, but limited formability and it recrystallizes above ~1100 °C. Yield strength is 200 MPa in Annealed versus 500 MPa in CW.
How much does R04261 cost?
R04261 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 B393 — Niobium and Niobium Alloy Strip, Sheet, and Plate (Type 4, R04261) — ASTM International (2018)
- ASTM B392 — Niobium and Niobium Alloy Bar, Rod, and Wire — ASTM International (2020)
- ASTM B391 — Niobium and Niobium Alloy Ingots — ASTM International (2018)
- ASTM B394 — Niobium and Niobium Alloy Seamless and Welded Tubes — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (niobium and tantalum) — ASM International (2005)
- Niobium and Nb-1Zr mill product datasheets — refractory-metal producers (e.g. H.C. Starck / Ningxia Orient Tantalum) (2022)
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.