Titanium Ti Grade 25-STA (Solution treated and aged)
Heat-treated state
UNS R56403
Choose for maximum strength in thin sections (downhole tubulars, fasteners); slightly lower toughness and ductility than annealed.
Values for the STA condition
Other Ti Grade 25 tempers and conditions
Ti Grade 25 is listed in 4 conditions; see the grade overview at Ti Grade 25.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
above beta transus anneal, slow cooled | Pick when fracture toughness and damage tolerance in thick sections matter more than ductility or fatigue life. | 860 | 940 | 10 | 34 HRC | 1 % IACS |
AnnealedDefault mill annealed (ASTM B265/B348 Grade 25) | Standard stock condition for plate, sheet, bar and pipe; best combination of ductility, weldability and corrosion resistance. | 880 | 950 | 14 | 35 HRC | — |
GTAW weld metal / HAZ, unstress-relieved | Property set for autogenous or matching-filler GTAW joints before post-weld stress relief; ductility drops appreciably. | 890 | 960 | 7 | 37 HRC | 1 % IACS |
STAThis page Solution treated and aged | Choose for maximum strength in thin sections (downhole tubulars, fasteners); slightly lower toughness and ductility than annealed. | 1,010 | 1,100 | 10 | 39 HRC | — |
What is Ti Grade 25-STA?
Ti Grade 25-STA is Ti Grade 25 heat treated to STA — choose for maximum strength in thin sections (downhole tubulars, fasteners); slightly lower toughness and ductility than annealed. Ti Grade 25-STA has a yield strength of 1,010 MPa (146 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 93% of titanium grades. Elongation at break is 10% and the elastic modulus is 113 GPa (16.4 Msi). Ti Grade 25-STA has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F). Annealed is the default condition FabDigit quotes; STA is available on request or by drawing note.
Advantages
- Low embodied carbon — 35 kg CO₂/kg, better than 100% of titanium grades
- High strength — 1,010 MPa (146 ksi), better than 93% of titanium grades
Limitations
- Limited formability — 12/100, worse than 97% of titanium grades
- Limited ductility — 10%, worse than 93% of titanium grades
- Poor heat conductor — 6.7 W/m·K (3.87 BTU/hr·ft·°F), worse than 92% of titanium grades
- Difficult to weld — 45/100, worse than 92% of titanium grades
- Low electrical conductivity — 1 % IACS, worse than 89% of titanium grades
Ti Grade 25-STA properties
Typical room-temperature values for Ti Grade 25-STA; 13 are specific to this condition. Other listed values are Ti Grade 25 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Ti Grade 25-STA has a density of 4.43 g/cm³ (0.16 lb/in³), lighter than 89% of titanium grades. It melts at 1,604°C (2,919 °F).
Mechanical16
Ti Grade 25-STA has a yield strength of 1,010 MPa (146 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 93% of titanium grades. Elongation at break is 10% and the elastic modulus is 113 GPa (16.4 Msi).
Thermal6
Ti Grade 25-STA is rated for continuous service to 350°C (662 °F). It conducts heat at 6.7 W/m·K (3.87 BTU/hr·ft·°F), worse than 92% of titanium grades. Thermal expansion is 8.7 µm/m·K (4.83 µin/in·°F).
Electrical3
Ti Grade 25-STA conducts electricity at 1 % IACS, worse than 89% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (95/100), better than 83% of titanium grades.
Sustainability4
Producing a kilogram of Ti Grade 25-STA takes about 640 MJ of energy and emits 35 kg of CO₂ — less than 93% of titanium grades. Typical recycled content is 25%.
Manufacturability8
Ti Grade 25-STA's machinability is poor (16/100, worse than 93% of titanium grades); weldability fair (45/100); formability not recommended (12/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ti Grade 25-STA
Is Ti Grade 25 easy to machine?
Machine like Ti-6Al-4V: rigid setups, sharp uncoated-carbide or PVD tools, ~30–60 m/min surface speed, heavy flood coolant, never dwell in the cut.
Can Ti Grade 25 be welded?
GTAW/EBW/plasma with full inert shielding and trailing/backing gas; clean joints, keep interstitial pickup low, use matching Gr.25 or ERTi-5 filler.
Can Ti Grade 25 be formed, bent or molded?
Cold formability is limited (bend radii ≥4–5t); hot form or superplastic form at 750–900 °C, then descale and pickle.
What surface finishes work on Ti Grade 25?
Pickle in HNO3/HF after hot work to remove alpha case; colour anodize or polish; avoid chloride-bearing marking inks before heat treatment.
Ti Grade 25 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 |
|---|---|---|
| Al | 5.5 – 6.75 | 6.2 |
| V | 3.5 – 4.5 | 4 |
| Ni | 0.3 – 0.8 | 0.5 |
| Pd | 0.04 – 0.08 | 0.06 |
| Fe | ≤ 0.4 | 0.2 |
| O | ≤ 0.2 | 0.15 |
| C | ≤ 0.08 | 0.02 |
| N | ≤ 0.05 | 0.02 |
| H0.0125 % max for sheet/strip per B265 | ≤ 0.02 | 0.01 |
| Residuals, each | ≤ 0.1 | — |
| Residuals, total | ≤ 0.4 | — |
| Ti | balance | — |
Ti Grade 25-STA — frequently asked
What is Ti Grade 25-STA used for?
Ti Grade 25-STA is typically used for oil and gas downhole components, marine high-strength hardware, subsea valve and pump internals, seawater-service fasteners and studs, chloride-service pressure-retaining forgings and wellhead and completion tooling parts. In short: grade 5 strength, crevice resistant; built for hot chlorides; high-cost alloy addition.
What is the yield strength of Ti Grade 25-STA?
Ti Grade 25-STA has a typical yield strength of 1,010 MPa (146 ksi) and a tensile strength of 1,100 MPa (160 ksi) — stronger than 93% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is Ti Grade 25-STA easy to machine?
Not especially — machinability is rated poor (16/100, worse than 93% of titanium grades). Machine like Ti-6Al-4V: rigid setups, sharp uncoated-carbide or PVD tools, ~30–60 m/min surface speed, heavy flood coolant, never dwell in the cut.
Can Ti Grade 25-STA be welded?
With care — weldability is rated fair (45/100). GTAW/EBW/plasma with full inert shielding and trailing/backing gas; clean joints, keep interstitial pickup low, use matching Gr.25 or ERTi-5 filler.
What surface finishes work on Ti Grade 25-STA?
Pickle in HNO3/HF after hot work to remove alpha case; colour anodize or polish; avoid chloride-bearing marking inks before heat treatment.
Can Ti Grade 25-STA be formed, bent or molded?
Cold formability is limited (bend radii ≥4–5t); hot form or superplastic form at 750–900 °C, then descale and pickle.
What is the maximum service temperature of Ti Grade 25-STA?
Ti Grade 25-STA is rated for continuous use to about 350°C (662 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ti Grade 25 Annealed and Ti Grade 25-STA?
Annealed is the default condition — standard stock condition for plate, sheet, bar and pipe; best combination of ductility, weldability and corrosion resistance. STA: choose for maximum strength in thin sections (downhole tubulars, fasteners); slightly lower toughness and ductility than annealed. Yield strength is 880 MPa in Annealed versus 1,010 MPa in STA.
Sources
- ASTM B265 – Titanium and Titanium Alloy Strip, Sheet and Plate — ASTM International (2020)
- ASTM B348 – Titanium and Titanium Alloy Bars and Billets — ASTM International (2021)
- ASTM B861 – Titanium and Titanium Alloy Seamless Pipe — ASTM International (2019)
- ASM Handbook Vol. 2 – Properties and Selection: Nonferrous Alloys — ASM International (1990)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- MMPDS Ti-6Al-4V design allowables — Battelle/FAA (2023)
- Corrosion-resistant titanium alloy grades (Gr.7/Gr.16/Gr.24/Gr.25) data — Titanium mill producer literature (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.