Titanium Ti-5Al-5Sn-2Zr-2Mo-STA (Solution treated and aged)
Heat-treated state
Pick when maximum room-temperature strength is required in thinner sections; ductility and toughness drop.
Values for the STA condition
Other Ti-5Al-5Sn-2Zr-2Mo tempers and conditions
Ti-5Al-5Sn-2Zr-2Mo is listed in 5 conditions; see the grade overview at Ti-5Al-5Sn-2Zr-2Mo.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Mill Annealed | Lowest-cost as-supplied condition for bar and plate that will be re-heat-treated or lightly loaded. | 910 | 1,000 | 13 | 32 HRC | — |
Stress relieved | Forging/weldment supply condition to remove residual stress before final machining and heat treatment. | 930 | 1,020 | 11 | 33 HRC | 1.1 % IACS |
DADefault Duplex Annealed | The standard airframe/rocket-case condition: balanced strength, ductility and thermal stability to ~480 °C. | 950 | 1,035 | 12 | 34 HRC | — |
Beta STA | Beta-processed route with an ageing step: creep and toughness of BA with a modest strength recovery. | 960 | 1,060 | 7 | 35 HRC | 1.1 % IACS |
STAThis page Solution treated and aged | Pick when maximum room-temperature strength is required in thinner sections; ductility and toughness drop. | 1,050 | 1,150 | 9 | 37 HRC | — |
What is Ti-5Al-5Sn-2Zr-2Mo-STA?
Ti-5Al-5Sn-2Zr-2Mo-STA is Ti-5Al-5Sn-2Zr-2Mo heat treated to STA — pick when maximum room-temperature strength is required in thinner sections; ductility and toughness drop. Ti-5Al-5Sn-2Zr-2Mo-STA has a yield strength of 1,050 MPa (152 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 96% of titanium grades. Elongation at break is 9% and the elastic modulus is 117 GPa (17 Msi). Ti-5Al-5Sn-2Zr-2Mo-STA has a density of 4.55 g/cm³ (0.164 lb/in³), heavier than 84% of titanium grades. It melts at 1,600°C (2,912 °F). DA is the default condition FabDigit quotes; STA is available on request or by drawing note.
Advantages
- High strength — 1,050 MPa (152 ksi), better than 96% of titanium grades
- High service temperature — 450°C (842 °F), better than 87% of titanium grades
Limitations
- Low fracture toughness — 42 MPa·√m (38.2 ksi·√in), worse than 99% of titanium grades
- Limited ductility — 9%, worse than 97% of titanium grades
- Limited formability — 12/100, worse than 97% of titanium grades
- Hard to polish — 60/100, worse than 97% of titanium grades
- Difficult to weld — 55/100, worse than 87% of titanium grades
Ti-5Al-5Sn-2Zr-2Mo-STA properties
Typical room-temperature values for Ti-5Al-5Sn-2Zr-2Mo-STA; 12 are specific to this condition. Other listed values are Ti-5Al-5Sn-2Zr-2Mo reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Ti-5Al-5Sn-2Zr-2Mo-STA has a density of 4.55 g/cm³ (0.164 lb/in³), heavier than 84% of titanium grades. It melts at 1,600°C (2,912 °F).
Mechanical16
Ti-5Al-5Sn-2Zr-2Mo-STA has a yield strength of 1,050 MPa (152 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 96% of titanium grades. Elongation at break is 9% and the elastic modulus is 117 GPa (17 Msi).
Thermal6
Ti-5Al-5Sn-2Zr-2Mo-STA is rated for continuous service to 450°C (842 °F). It conducts heat at 7.5 W/m·K (4.33 BTU/hr·ft·°F), worse than 65% of titanium grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).
Electrical3
Ti-5Al-5Sn-2Zr-2Mo-STA conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.
Sustainability4
Producing a kilogram of Ti-5Al-5Sn-2Zr-2Mo-STA takes about 700 MJ of energy and emits 42 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 25%.
Manufacturability8
Ti-5Al-5Sn-2Zr-2Mo-STA's machinability is poor (15/100, worse than 97% of titanium grades); weldability good (55/100); 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-5Al-5Sn-2Zr-2Mo-STA
Is Ti-5Al-5Sn-2Zr-2Mo easy to machine?
Machine like Ti-6Al-4V but slower: rigid setup, sharp uncoated carbide or PVD-coated tools, 20–40 m/min turning, heavy flood coolant, positive rake and no dwelling to avoid work hardening and fire risk from fine chips.
Can Ti-5Al-5Sn-2Zr-2Mo be welded?
GTAW, plasma or EBW in high-purity argon or vacuum with full back-purge; use matching filler, keep interstitials low, and stress-relieve/stabilize at 595–790 °C after welding to restore toughness.
Can Ti-5Al-5Sn-2Zr-2Mo be formed, bent or molded?
Cold formability is poor — bend and draw hot at 700–900 °C or use hot sizing/creep forming with generous bend radii (≥4–5 t) and post-form stress relief.
What surface finishes work on Ti-5Al-5Sn-2Zr-2Mo?
Chemical mill or pickle in HNO₃/HF to remove alpha case after hot work; blue-etch anodize for inspection, Type II anodize for colour, and plasma nitride, ion plating or dry-film lube for wear/galling surfaces.
Ti-5Al-5Sn-2Zr-2Mo 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 |
|---|---|---|
| Alα stabilizer | 4.5 – 5.5 | 5 |
| Snneutral/α strengthener | 4.5 – 5.5 | 5 |
| Zr | 1.5 – 2.5 | 2 |
| Moβ stabilizer | 1.5 – 2.5 | 2 |
| Sipresent in the Ti-5522S creep-resistant version; omitted in the base Si-free composition | 0.15 – 0.35 | 0.25 |
| Fe | ≤ 0.15 | — |
| Omax; kept low for thermal stability | ≤ 0.13 | 0.1 |
| C | ≤ 0.05 | — |
| N | ≤ 0.04 | — |
| H | ≤ 0.01 | — |
| Ti | balance | — |
Ti-5Al-5Sn-2Zr-2Mo-STA — frequently asked
What is Ti-5Al-5Sn-2Zr-2Mo-STA used for?
Ti-5Al-5Sn-2Zr-2Mo-STA is typically used for airframe structures, rocket motor cases and high-temperature fasteners. In short: near-alpha for 480 °C service; creep-resistant airframe forging alloy; stronger than Ti-6Al-4V hot.
What is the yield strength of Ti-5Al-5Sn-2Zr-2Mo-STA?
Ti-5Al-5Sn-2Zr-2Mo-STA has a typical yield strength of 1,050 MPa (152 ksi) and a tensile strength of 1,150 MPa (167 ksi) — stronger than 96% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Ti-5Al-5Sn-2Zr-2Mo-STA easy to machine?
Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machine like Ti-6Al-4V but slower: rigid setup, sharp uncoated carbide or PVD-coated tools, 20–40 m/min turning, heavy flood coolant, positive rake and no dwelling to avoid work hardening and fire risk from fine chips.
Can Ti-5Al-5Sn-2Zr-2Mo-STA be welded?
Yes — weldability is rated good (55/100). GTAW, plasma or EBW in high-purity argon or vacuum with full back-purge; use matching filler, keep interstitials low, and stress-relieve/stabilize at 595–790 °C after welding to restore toughness.
What surface finishes work on Ti-5Al-5Sn-2Zr-2Mo-STA?
Chemical mill or pickle in HNO₃/HF to remove alpha case after hot work; blue-etch anodize for inspection, Type II anodize for colour, and plasma nitride, ion plating or dry-film lube for wear/galling surfaces.
Can Ti-5Al-5Sn-2Zr-2Mo-STA be formed, bent or molded?
Cold formability is poor — bend and draw hot at 700–900 °C or use hot sizing/creep forming with generous bend radii (≥4–5 t) and post-form stress relief.
What is the maximum service temperature of Ti-5Al-5Sn-2Zr-2Mo-STA?
Ti-5Al-5Sn-2Zr-2Mo-STA is rated for continuous use to about 450°C (842 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ti-5Al-5Sn-2Zr-2Mo-DA and Ti-5Al-5Sn-2Zr-2Mo-STA?
DA is the default condition — the standard airframe/rocket-case condition: balanced strength, ductility and thermal stability to ~480 °C. STA: pick when maximum room-temperature strength is required in thinner sections; ductility and toughness drop. Yield strength is 950 MPa in DA versus 1,050 MPa in STA.
Sources
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials — ASM International (1990)
- Titanium: A Technical Guide, 2nd ed. — ASM International (2000)
- ASTM B348 / AMS specifications for titanium alloy bar and billet — ASTM / SAE (2021)
- ASM Handbook Vol. 13B — Corrosion: Materials — ASM International (2005)
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.