Refractory Metal R05400
UNS R05400 · ASTM B365
R05400 is powder-metallurgy consolidated unalloyed tantalum, pressed and sintered from tantalum powder into ingot as feedstock for capacitor and mill products, and covered by ASTM B365.
Reference datasheet — R05400 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 O condition
R05400 tempers and conditions
R05400 is supplied in 3 conditions, soft to hard. O is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ODefault Annealed | Default stocked condition: maximum ductility for deep drawing, spinning and lining fabrication. | 170 | 250 | 35 | 90 HB | 12.8 % IACS |
Stress relieved | Intermediate condition: relieves cold-work stresses and improves dimensional stability while retaining much of the cold-worked strength. | 310 | 400 | 15 | 140 HB | 12.5 % IACS |
Cold worked | Pick when higher strength and stiffness of thin foil, wire or springs matters more than formability. | 480 | 550 | 5 | 185 HB | 12.1 % IACS |
Supply forms, finishes and certifications
Ways R05400 is supplied — form, process route, surface or paperwork — without a datasheet of their own. The property values above apply.
| Option | What it is | Type |
|---|---|---|
AS | As-sintered ingot / bar | Coating |
What is R05400?
R05400 is powder-metallurgy consolidated unalloyed tantalum, pressed and sintered from tantalum powder into ingot as feedstock for capacitor and mill products, and covered by ASTM B365. It combines near-complete resistance to acids (corrosion score 98) with outstanding cold formability (score 95) at 170 MPa yield, 250 MPa tensile, 35% elongation and 90 HB (48 HRB), plus 186 GPa modulus, 57 W/m·K conductivity and 12.8% IACS. The limits are cost, low strength and rapid oxidation in air above roughly 300 °C. Ta-10W is the choice when higher strength is required. R05400 has a density of 16.6 g/cm³ (0.6 lb/in³), heavier than 84% of refractory metal grades. It melts at 3,017°C (5,463 °F). R05400 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Elongation at break is 35% and the elastic modulus is 186 GPa (27 Msi).
What is R05400 used for?
- capacitor anode powder feedstock
- sputtering target blanks
- mill product starting stock
- electronic grade tantalum components
Advantages
- Good corrosion resistance — 98/100, better than 100% of refractory metal grades
- Forms and bends easily — 95/100, better than 99% of refractory metal grades
- Tough — resists crack growth — 100 MPa·√m (91 ksi·√in), better than 98% of refractory metal grades
- Ductile — tolerates forming and impact — 35%, better than 93% of refractory metal grades
- Readily welded — 78/100, better than 86% of refractory metal grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 95% of refractory metal grades
- Low strength — 170 MPa (24.7 ksi), worse than 93% of refractory metal grades
- High embodied carbon — 250 kg CO₂/kg, worse than 89% of refractory metal grades
- Heavy — 16.6 g/cm³ (0.6 lb/in³), worse than 84% of refractory metal grades
R05400 properties
Typical room-temperature values for R05400-O; bars are the position among refractory metal grades.
Physical3
R05400 has a density of 16.6 g/cm³ (0.6 lb/in³), heavier than 84% of refractory metal grades. It melts at 3,017°C (5,463 °F).
Mechanical14
R05400 has a yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Elongation at break is 35% and the elastic modulus is 186 GPa (27 Msi).
Thermal6
R05400 is rated for continuous service to 300°C (572 °F). It conducts heat at 57 W/m·K (32.9 BTU/hr·ft·°F), better than 68% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).
Electrical3
R05400 conducts electricity at 12.8 % IACS, better than 69% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (98/100), better than 100% of refractory metal grades.
Sustainability4
Producing a kilogram of R05400 takes about 4,000 MJ of energy and emits 250 kg of CO₂ — more than 89% of refractory metal grades. Typical recycled content is 30%.
Manufacturability8
R05400's machinability is poor (22/100, worse than 73% of refractory metal grades); weldability very good (78/100); formability excellent (95/100).
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. R05400 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with R05400
Is R05400 easy to machine?
Very gummy and galling-prone — use sharp, highly positive-rake carbide or HSS tools, heavy chlorinated or sulfurized coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing; never let the tool dwell.
Can R05400 be welded?
GTAW in a high-purity argon glovebox, EB or laser welding only; any pickup of O₂, N₂ or H₂ during welding causes severe embrittlement, and Ta must not be welded to Fe/Ni alloys directly.
Can R05400 be formed, bent or molded?
Outstanding cold formability — deep draws, spinning and >90 % cold rolling are routine with clean tooling and non-galling lubricants; vacuum anneal at 1100–1300 °C to restore ductility between severe operations.
R05400 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 |
|---|---|---|
| Nbcolumbium | ≤ 0.1 | 0.03 |
| W | ≤ 0.05 | 0.01 |
| Mo | ≤ 0.02 | 0.01 |
| Ti | ≤ 0.01 | 0 |
| Fe | ≤ 0.01 | 0 |
| Ni | ≤ 0.01 | 0 |
| Si | ≤ 0.01 | 0 |
| C | ≤ 0.01 | 0 |
| Ohigher than EB-melted R05200 (0.015 max) because of powder-metallurgy route | ≤ 0.03 | 0.02 |
| N | ≤ 0.01 | 0 |
| H | ≤ 0 | 5×10⁻⁴ |
| Ta99.9 % min (Ta+Nb basis per ASTM B365/B708 Type 2) | balance |
What surface finishes work on R05400?
Chemically clean/pickle in HF–HNO₃ then electropolish; anodizing in dilute phosphoric or citric electrolyte builds a controlled Ta₂O₅ film for dielectric or colored finishes; avoid abrasive smearing.
Equivalent designations
Standards and trade names that resolve to Refractory Metal R05400 in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- ASTM
- B365
- Also called
- Sintered Ta
How much does R05400 cost?
R05400 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.
R05400 — frequently asked
What is R05400 used for?
R05400 is typically used for capacitor anode powder feedstock, sputtering target blanks, mill product starting stock and electronic grade tantalum components. In short: baseline unalloyed tantalum; near-inert to acids; deep-draw capable.
What is the yield strength of R05400?
R05400 has a typical yield strength of 170 MPa (24.7 ksi) and a tensile strength of 250 MPa (36.3 ksi) — weaker than 93% of refractory metal grades. Strength varies by condition: see the 3 listed tempers.
Is R05400 easy to machine?
Not especially — machinability is rated poor (22/100, worse than 73% of refractory metal grades). Very gummy and galling-prone — use sharp, highly positive-rake carbide or HSS tools, heavy chlorinated or sulfurized coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing; never let the tool dwell.
Can R05400 be welded?
Yes — weldability is rated very good (78/100). GTAW in a high-purity argon glovebox, EB or laser welding only; any pickup of O₂, N₂ or H₂ during welding causes severe embrittlement, and Ta must not be welded to Fe/Ni alloys directly.
What surface finishes work on R05400?
Chemically clean/pickle in HF–HNO₃ then electropolish; anodizing in dilute phosphoric or citric electrolyte builds a controlled Ta₂O₅ film for dielectric or colored finishes; avoid abrasive smearing.
Can R05400 be formed, bent or molded?
Outstanding cold formability — deep draws, spinning and >90 % cold rolling are routine with clean tooling and non-galling lubricants; vacuum anneal at 1100–1300 °C to restore ductility between severe operations.
What is the maximum service temperature of R05400?
R05400 is rated for continuous use to about 300°C (572 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between R05400-O and R05400-CW?
O is the default condition — default stocked condition: maximum ductility for deep drawing, spinning and lining fabrication. CW: pick when higher strength and stiffness of thin foil, wire or springs matters more than formability. Yield strength is 170 MPa in O versus 480 MPa in CW.
How much does R05400 cost?
R05400 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 B365 — Tantalum and Tantalum Alloy Rod and Wire — ASTM International (2018)
- ASTM B708 — Tantalum and Tantalum Alloy Plate, Sheet and Strip — ASTM International (2021)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
- CRC Handbook of Chemistry and Physics — physical properties of tantalum — CRC Press (2023)
- Tantalum mill product data (sheet, rod, wire) — Global Advanced Metals / H.C. Starck Solutions (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.