Titanium Ti Grade 20-ST (Solution annealed)
Heat-treated state · default condition
UNS R58645
Choose for maximum cold formability/cold drawing and for parts to be aged after fabrication.
Values for the ST condition
Other Ti Grade 20 tempers and conditions
Ti Grade 20 is listed in 5 conditions; see the grade overview at Ti Grade 20.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
STDefaultThis page Solution annealed | Choose for maximum cold formability/cold drawing and for parts to be aged after fabrication. | 820 | 860 | 18 | 30 HRC | — |
STA | Choose for a balance of ~1000–1100 MPa strength with better ductility and toughness than the high-strength age. | 1,000 | 1,080 | 11 | 36 HRC | — |
Cold worked | Choose for cold-drawn spring wire and thin tube where high strength is obtained by cold work without ageing. | 1,030 | 1,100 | 8 | 36 HRC | 1.2 % IACS |
STA | Choose when maximum heat-treated strength (≥1170 MPa) is needed and limited ductility/toughness is acceptable. | 1,210 | 1,290 | 7 | 42 HRC | — |
Cold worked and aged | Choose for high-strength corrosion-resistant springs and fasteners where cold work plus ageing maximizes strength. | 1,310 | 1,400 | 5 | 45 HRC | 1.3 % IACS |
What is Ti Grade 20-ST?
Ti Grade 20-ST is Ti Grade 20 heat treated to ST — choose for maximum cold formability/cold drawing and for parts to be aged after fabrication. Ti Grade 20-ST has a yield strength of 820 MPa (119 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 62% of titanium grades. Elongation at break is 18% and the elastic modulus is 95 GPa (13.8 Msi). Ti Grade 20-ST has a density of 4.82 g/cm³ (0.174 lb/in³), heavier than 94% of titanium grades. It melts at 1,620°C (2,948 °F).
Limitations
- Limited service temperature — 260°C (500 °F), worse than 97% of titanium grades
- High embodied carbon — 48 kg CO₂/kg, worse than 95% of titanium grades
- Difficult to weld — 55/100, worse than 87% of titanium grades
- Poor heat conductor — 6.8 W/m·K (3.93 BTU/hr·ft·°F), worse than 86% of titanium grades
Ti Grade 20-ST properties
Typical room-temperature values for Ti Grade 20-ST; 17 are specific to this condition. Other listed values are Ti Grade 20 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
Ti Grade 20-ST has a density of 4.82 g/cm³ (0.174 lb/in³), heavier than 94% of titanium grades. It melts at 1,620°C (2,948 °F).
Mechanical14
Ti Grade 20-ST has a yield strength of 820 MPa (119 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 62% of titanium grades. Elongation at break is 18% and the elastic modulus is 95 GPa (13.8 Msi).
Thermal6
Ti Grade 20-ST is rated for continuous service to 260°C (500 °F). It conducts heat at 6.8 W/m·K (3.93 BTU/hr·ft·°F), worse than 86% of titanium grades. Thermal expansion is 9 µm/m·K (5 µin/in·°F).
Electrical3
Ti Grade 20-ST conducts electricity at 1.2 % IACS, worse than 55% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (94/100), better than 80% of titanium grades.
Sustainability4
Producing a kilogram of Ti Grade 20-ST takes about 700 MJ of energy and emits 48 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 20%.
Manufacturability8
Ti Grade 20-ST's machinability is poor (22/100, worse than 55% of titanium grades); weldability good (55/100); formability very good (70/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Ti Grade 20-ST
Is Ti Grade 20 easy to machine?
Machine like a hard β-Ti alloy: rigid setup, sharp carbide/PCD tools, low surface speed (~20–35 m/min aged), heavy flood coolant, positive rake and constant feed to avoid work hardening and galling.
Can Ti Grade 20 be welded?
GTAW/EBW/laser weld with full inert or vacuum shielding and matching Grade 19/20 filler; weld in the solution-treated state and age afterwards, since as-welded aged joints lose ductility.
Can Ti Grade 20 be formed, bent or molded?
Excellent cold formability and cold drawability in the solution-treated β condition (springs, thin tube); hot work 815–900 °C, and expect essentially no cold forming after ageing.
What surface finishes work on Ti Grade 20?
Pickle/grit-blast plus HNO3-HF descale to remove alpha case; anodize (AMS 2488) or ion-nitride for galling resistance; polishes to a bright hard finish, no plating normally required for corrosion.
Ti Grade 20 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 | 3 – 4 | 3.5 |
| V | 7.5 – 8.5 | 8 |
| Cr | 5.5 – 6.5 | 6 |
| Mo | 3.5 – 4.5 | 4 |
| Zr | 3.5 – 4.5 | 4 |
| Pdthe addition distinguishing Grade 20 from Grade 19 | 0.04 – 0.08 | 0.06 |
| Fe | ≤ 0.3 | — |
| Omax, product-form dependent | ≤ 0.14 | 0.1 |
| C | ≤ 0.05 | — |
| N | ≤ 0.03 | — |
| Hmax (0.015 for sheet/strip) | ≤ 0.02 | — |
| other, eachresidual, each | ≤ 0.1 | — |
| other, totalresidual, total | ≤ 0.4 | — |
| Ti | balance | — |
Ti Grade 20-ST — frequently asked
What is Ti Grade 20-ST used for?
Ti Grade 20-ST is typically used for high-strength fasteners in corrosive environments, aerospace structural components, subsea and seawater bolting, springs for chloride service, downhole tool components and chemical plant tie rods and studs. In short: corrosion-resistant Beta C; highest-strength Pd titanium; difficult to machine.
What is the yield strength of Ti Grade 20-ST?
Ti Grade 20-ST has a typical yield strength of 820 MPa (119 ksi) and a tensile strength of 860 MPa (125 ksi) — stronger than 62% of titanium grades. Strength varies by condition: see the 5 listed tempers.
Is Ti Grade 20-ST easy to machine?
Not especially — machinability is rated poor (22/100, worse than 55% of titanium grades). Machine like a hard β-Ti alloy: rigid setup, sharp carbide/PCD tools, low surface speed (~20–35 m/min aged), heavy flood coolant, positive rake and constant feed to avoid work hardening and galling.
Can Ti Grade 20-ST be welded?
Yes — weldability is rated good (55/100). GTAW/EBW/laser weld with full inert or vacuum shielding and matching Grade 19/20 filler; weld in the solution-treated state and age afterwards, since as-welded aged joints lose ductility.
What surface finishes work on Ti Grade 20-ST?
Pickle/grit-blast plus HNO3-HF descale to remove alpha case; anodize (AMS 2488) or ion-nitride for galling resistance; polishes to a bright hard finish, no plating normally required for corrosion.
Can Ti Grade 20-ST be formed, bent or molded?
Excellent cold formability and cold drawability in the solution-treated β condition (springs, thin tube); hot work 815–900 °C, and expect essentially no cold forming after ageing.
What is the maximum service temperature of Ti Grade 20-ST?
Ti Grade 20-ST is rated for continuous use to about 260°C (500 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Ti Grade 20-ST and Ti Grade 20 STA-HS?
ST is the default condition — choose for maximum cold formability/cold drawing and for parts to be aged after fabrication. STA-HS: choose when maximum heat-treated strength (≥1170 MPa) is needed and limited ductility/toughness is acceptable. Yield strength is 820 MPa in ST versus 1,210 MPa in STA-HS.
Sources
- ASTM B265 — Titanium and Titanium Alloy Strip, Sheet, and Plate (Grade 20) — ASTM International (2020)
- ASTM B348 — Titanium and Titanium Alloy Bars and Billets (Grade 20) — ASTM International (2021)
- ASTM B381 — Titanium and Titanium Alloy Forgings — ASTM International (2019)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys (Beta C / Ti-3Al-8V-6Cr-4Mo-4Zr) — ASM International (1990)
- ASM Handbook Vol. 13B — Corrosion: Materials (Titanium and Pd-modified grades) — ASM International (2005)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- Beta-C / Ti-3-8-6-4-4 alloy technical data — ATI / Carpenter (2020)
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.