Titanium Ti-6-22-22 BSTOA
Heat-treated state
UNS R56223
BSTOA = beta solution treated and overaged
Compromise heat treatment giving near-STA strength with markedly better toughness; used for heavy airframe forgings.
Values for the BSTOA condition
Other Ti-6-22-22 tempers and conditions
Ti-6-22-22 is listed in 5 conditions; see the grade overview at Ti-6-22-22.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Solution annealed | Intermediate condition supplied when the part is to be formed or straightened before final ageing. | 900 | 1,000 | 14 | 32 HRC | 1 % IACS |
Recrystallization annealed | Damage-tolerant plate condition: equiaxed structure with good toughness and stable fatigue-crack-growth behaviour. | 910 | 1,000 | 12 | 33 HRC | 1 % IACS |
mill/duplex annealed (alpha-beta anneal) | Softest supply condition for machining stock and subsequent hot forming; strength well below the aged capability. | 950 | 1,035 | 13 | 33 HRC | — |
BSTOAThis page Beta solution treated and overaged | Compromise heat treatment giving near-STA strength with markedly better toughness; used for heavy airframe forgings. | 1,035 | 1,140 | 9 | 36 HRC | 1 % IACS |
STADefault Solution treated and aged | Standard high-strength condition for airframe forgings, plate and machined fittings; best strength-to-toughness balance. | 1,160 | 1,240 | 10 | 38 HRC | — |
What is Ti-6-22-22 BSTOA?
Ti-6-22-22 BSTOA is Ti-6-22-22 heat treated to BSTOA — compromise heat treatment giving near-STA strength with markedly better toughness; used for heavy airframe forgings. Ti-6-22-22 BSTOA has a yield strength of 1,035 MPa (150 ksi) and a tensile strength of 1,140 MPa (165 ksi) — stronger than 95% of titanium grades. Elongation at break is 9% and the elastic modulus is 114 GPa (16.5 Msi). Ti-6-22-22 BSTOA has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,590°C (2,894 °F). STA is the default condition FabDigit quotes; BSTOA is available on request or by drawing note.
Advantages
- High strength — 1,035 MPa (150 ksi), better than 95% of titanium grades
Limitations
- Limited ductility — 9%, worse than 97% of titanium grades
- Hard to polish — 60/100, worse than 97% of titanium grades
- Limited formability — 15/100, worse than 93% 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-6-22-22 BSTOA properties
Typical room-temperature values for Ti-6-22-22 BSTOA; 22 are specific to this condition. Other listed values are Ti-6-22-22 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Ti-6-22-22 BSTOA has a density of 4.65 g/cm³ (0.168 lb/in³), heavier than 90% of titanium grades. It melts at 1,590°C (2,894 °F).
Mechanical15
Ti-6-22-22 BSTOA has a yield strength of 1,035 MPa (150 ksi) and a tensile strength of 1,140 MPa (165 ksi) — stronger than 95% of titanium grades. Elongation at break is 9% and the elastic modulus is 114 GPa (16.5 Msi).
Thermal6
Ti-6-22-22 BSTOA is rated for continuous service to 340°C (644 °F). It conducts heat at 7.2 W/m·K (4.16 BTU/hr·ft·°F), worse than 67% of titanium grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).
Electrical3
Ti-6-22-22 BSTOA conducts electricity at 1 % IACS, worse than 89% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (88/100), worse than 77% of titanium grades.
Sustainability4
Producing a kilogram of Ti-6-22-22 BSTOA takes about 650 MJ of energy and emits 42 kg of CO₂ — less than 75% of titanium grades. Typical recycled content is 25%.
Manufacturability7
Ti-6-22-22 BSTOA's machinability is poor (17/100, worse than 89% of titanium grades); weldability fair (45/100); formability poor (15/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ti-6-22-22 BSTOA
Is Ti-6-22-22 easy to machine?
Treat as harder-than-Ti-6Al-4V: rigid setups, low surface speed (~20–35 m/min carbide), heavy positive feed, flood coolant, and no dwell to avoid work hardening and edge chipping.
Can Ti-6-22-22 be welded?
GTAW/plasma/EB or laser with full inert shielding of hot zone; keep interstitials low, use matching or Ti-6Al-4V-class filler, and post-weld stress relieve/age since as-welded ductility is low.
Can Ti-6-22-22 be formed, bent or molded?
Hot form or hot size at 700–900 °C; cold forming in STA is impractical, generous bend radii and springback allowance are required even in the annealed condition.
What surface finishes work on Ti-6-22-22?
Grit blast/pickle to remove alpha case after hot work; Ti anodize or fluoride-phosphate conversion for anti-galling, dry-film lube or IVD Al where fretting/fastener contact occurs.
Ti-6-22-22 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 – 6.5 | 6 |
| Sn | 1.5 – 2.5 | 2 |
| Zr | 1.5 – 2.5 | 2 |
| Mo | 1.5 – 2.5 | 2 |
| Cr | 1.5 – 2.5 | 2 |
| Sithe '-22-22S' variant; some early heats made Si-free | 0.1 – 0.25 | 0.2 |
| Fe | ≤ 0.25 | — |
| O | ≤ 0.14 | — |
| C | ≤ 0.05 | — |
| N | ≤ 0.04 | — |
| Hmax, product-form dependent | ≤ 0.01 | — |
| Ti | balance | — |
Ti-6-22-22 BSTOA — frequently asked
What is Ti-6-22-22 BSTOA used for?
Ti-6-22-22 BSTOA is typically used for airframe structural components, high-strength fasteners, wing and fuselage forgings, bulkhead and frame fittings, landing gear structure and machined structural brackets. In short: damage-tolerant airframe alloy; higher strength than Ti-6Al-4V; hot forming required.
What is the yield strength of Ti-6-22-22 BSTOA?
Ti-6-22-22 BSTOA has a typical yield strength of 1,035 MPa (150 ksi) and a tensile strength of 1,140 MPa (165 ksi) — stronger than 95% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Ti-6-22-22 BSTOA easy to machine?
Not especially — machinability is rated poor (17/100, worse than 89% of titanium grades). Treat as harder-than-Ti-6Al-4V: rigid setups, low surface speed (~20–35 m/min carbide), heavy positive feed, flood coolant, and no dwell to avoid work hardening and edge chipping.
Can Ti-6-22-22 BSTOA be welded?
With care — weldability is rated fair (45/100). GTAW/plasma/EB or laser with full inert shielding of hot zone; keep interstitials low, use matching or Ti-6Al-4V-class filler, and post-weld stress relieve/age since as-welded ductility is low.
What surface finishes work on Ti-6-22-22 BSTOA?
Grit blast/pickle to remove alpha case after hot work; Ti anodize or fluoride-phosphate conversion for anti-galling, dry-film lube or IVD Al where fretting/fastener contact occurs.
Can Ti-6-22-22 BSTOA be formed, bent or molded?
Hot form or hot size at 700–900 °C; cold forming in STA is impractical, generous bend radii and springback allowance are required even in the annealed condition.
What is the maximum service temperature of Ti-6-22-22 BSTOA?
Ti-6-22-22 BSTOA is rated for continuous use to about 340°C (644 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ti-6-22-22-STA and Ti-6-22-22-ST?
STA is the default condition — standard high-strength condition for airframe forgings, plate and machined fittings; best strength-to-toughness balance. ST: intermediate condition supplied when the part is to be formed or straightened before final ageing. Yield strength is 1,160 MPa in STA versus 900 MPa in ST.
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)
- ASM Handbook Vol. 13B — Corrosion: Materials (titanium chapter) — ASM International (2005)
- MMPDS — Metallic Materials Properties Development and Standardization (titanium alloy typical data conventions) — Battelle/FAA (2023)
- AMS 2488 — Anodic Treatment of Titanium and Titanium Alloys — SAE International (2019)
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.