Refractory Metal Ta-2.5W Cold Worked
Supply condition
UNS R05252 · ASTM B365 · also Tantalum-Tungsten
Highest strength and springback; used for hard sheet, foil, fasteners and wire where no further forming or welding is planned.
Values for the Cold Worked condition
Other Ta-2.5W tempers and conditions
Ta-2.5W is listed in 4 conditions; see the grade overview at Ta-2.5W.
- EB Melted
- Vacuum Annealed
- Stress Relieved
- Cold Worked
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
EB Melted Ingot / As-Cast | Primary electron-beam melted ingot or sputtering-target blank stock, prior to breakdown forging/rolling; coarse grain and low strength. | 240 | 340 | 30 | 100 HB | 10 % IACS |
Vacuum AnnealedDefault fully recrystallized (default mill condition) | Standard supply condition for sheet, plate, rod and tube where maximum ductility, deep-drawability and weldability are required. | 310 | 415 | 28 | 115 HB | 9.9 % IACS |
partially recovered, not recrystallized | Choose when dimensional stability and higher strength are needed but some residual cold-work ductility must be kept, e.g. formed diaphragms and rupture discs. | 440 | 520 | 15 | 160 HB | 9.6 % IACS |
Cold WorkedThis page as-rolled / as-drawn hard temper | Highest strength and springback; used for hard sheet, foil, fasteners and wire where no further forming or welding is planned. | 620 | 690 | 5 | 20 HRC | 9.4 % IACS |
What is Ta-2.5W Cold Worked?
Ta-2.5W Cold Worked is Ta-2.5W supplied in the Cold Worked condition — highest strength and springback; used for hard sheet, foil, fasteners and wire where no further forming or welding is planned. Ta-2.5W Cold Worked has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 84% of refractory metal grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi). Ta-2.5W Cold Worked has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 87% of refractory metal grades. It melts at 3,030°C (5,486 °F). Vacuum Annealed is the default condition FabDigit quotes; Cold Worked is available on request or by drawing note.
Advantages
- Good corrosion resistance — 97/100, better than 97% of refractory metal grades
- Polishes to a fine finish — 80/100, better than 97% of refractory metal grades
- High strength — 620 MPa (89.9 ksi), better than 84% of refractory metal grades
Limitations
- Limited service temperature — 300°C (572 °F), worse than 95% of refractory metal grades
- High embodied carbon — 260 kg CO₂/kg, worse than 92% of refractory metal grades
- Heavy — 16.7 g/cm³ (0.603 lb/in³), worse than 87% of refractory metal grades
- Limited ductility — 5%, worse than 78% of refractory metal grades
Ta-2.5W Cold Worked properties
Typical room-temperature values for Ta-2.5W Cold Worked; 21 are specific to this condition. Other listed values are Ta-2.5W reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Ta-2.5W Cold Worked has a density of 16.7 g/cm³ (0.603 lb/in³), heavier than 87% of refractory metal grades. It melts at 3,030°C (5,486 °F).
Mechanical14
Ta-2.5W Cold Worked has a yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 84% of refractory metal grades. Elongation at break is 5% and the elastic modulus is 200 GPa (29 Msi).
Thermal6
Ta-2.5W Cold Worked is rated for continuous service to 300°C (572 °F). It conducts heat at 52 W/m·K (30 BTU/hr·ft·°F), better than 63% of refractory metal grades. Thermal expansion is 6.5 µm/m·K (3.61 µin/in·°F).
Electrical3
Ta-2.5W Cold Worked conducts electricity at 9.4 % IACS, better than 64% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is excellent (97/100), better than 97% of refractory metal grades.
Sustainability3
Producing a kilogram of Ta-2.5W Cold Worked takes about 4,400 MJ of energy and emits 260 kg of CO₂ — more than 94% of refractory metal grades. Typical recycled content is 20%.
Manufacturability8
Ta-2.5W Cold Worked's machinability is poor (28/100, worse than 58% of refractory metal grades); weldability good (65/100); formability poor (30/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ta-2.5W Cold Worked
Is Ta-2.5W easy to machine?
Very gummy and galling — use sharp positive-rake carbide, heavy flood of chlorinated or emulsion coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing and smearing.
Can Ta-2.5W be welded?
GTAW in a high-purity argon glove box, or electron-beam/laser welding in vacuum; any O/N/H pickup above ~300 °C embrittles the weld, so trailing shields and clean surfaces are mandatory.
Can Ta-2.5W be formed, bent or molded?
Excellent cold formability — deep drawing, spinning and bending to tight radii are routine in the annealed condition; use lubricants and non-steel tooling inserts to avoid galling and iron pickup.
What surface finishes work on Ta-2.5W?
Pickle in HF/HNO3 mixtures to remove oxide and iron smear, then vacuum anneal; electropolishing or anodic Ta2O5 films give clean, stable surfaces for chemical or implant service.
Ta-2.5W 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 |
|---|---|---|
| Wsolid-solution strengthener | 2 – 3.5 | 2.5 |
| Nb | ≤ 0.1 | — |
| Mo | ≤ 0.02 | — |
| Ti | ≤ 0.01 | — |
| Fe | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| C | ≤ 0.01 | — |
| O | ≤ 0.02 | — |
| N | ≤ 0.01 | — |
| H | ≤ 0 | — |
| Ta | balance | — |
Ta-2.5W Cold Worked — frequently asked
What is Ta-2.5W Cold Worked used for?
Ta-2.5W Cold Worked is typically used for chemical reactor liners and cladding, shell-and-tube heat exchangers, rupture discs and bursting diaphragms, thermowells and immersion heater sheaths, acid-service valve and pump components and furnace heat shields and support structures. In short: strengthened tantalum alloy.
What is the yield strength of Ta-2.5W Cold Worked?
Ta-2.5W Cold Worked has a typical yield strength of 620 MPa (89.9 ksi) and a tensile strength of 690 MPa (100 ksi) — stronger than 84% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is Ta-2.5W Cold Worked easy to machine?
Not especially — machinability is rated poor (28/100, worse than 58% of refractory metal grades). Very gummy and galling — use sharp positive-rake carbide, heavy flood of chlorinated or emulsion coolant, slow speeds (15–30 m/min) and generous feeds to avoid rubbing and smearing.
Can Ta-2.5W Cold Worked be welded?
Yes — weldability is rated good (65/100). GTAW in a high-purity argon glove box, or electron-beam/laser welding in vacuum; any O/N/H pickup above ~300 °C embrittles the weld, so trailing shields and clean surfaces are mandatory.
What surface finishes work on Ta-2.5W Cold Worked?
Pickle in HF/HNO3 mixtures to remove oxide and iron smear, then vacuum anneal; electropolishing or anodic Ta2O5 films give clean, stable surfaces for chemical or implant service.
Can Ta-2.5W Cold Worked be formed, bent or molded?
Excellent cold formability — deep drawing, spinning and bending to tight radii are routine in the annealed condition; use lubricants and non-steel tooling inserts to avoid galling and iron pickup.
What is the maximum service temperature of Ta-2.5W Cold Worked?
Ta-2.5W Cold Worked 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.
Sources
- ASTM B708 — Tantalum and Tantalum Alloy Plate, Sheet and Strip — ASTM International (2021)
- ASTM B365 — Tantalum and Tantalum Alloy Rod and Wire — ASTM International (2018)
- ASTM B521 — Tantalum and Tantalum Alloy Seamless and Welded Tubes — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
- Tantalum and tantalum alloys product data — Plansee / H.C. Starck Solutions (2022)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.