Chemical composition
Nominal: mid-range where both limits are given, the cap where only a maximum is, balance takes the remainder. Exact specified ranges below.
| Element | Name | Content % | |
|---|---|---|---|
| Main elements5 elements | |||
| Ti | Titanium | Bal. | |
| Mo | Molybdenum | 14 – 16% | |
| Al | Aluminium | 2.5 – 3.5% | |
| Nb | Niobium | 2.2 – 3.2% | |
| Si | Silicon | 0.15 – 0.25% | |
| Element | Name | Content % | |
|---|---|---|---|
| Minor & residual7 elements | |||
| Fe | Iron | ≤ 0.4% | |
| O | Oxygen | ≤ 0.17% | |
| C | Carbon | ≤ 0.05% | |
| N | Nitrogen | ≤ 0.03% | |
| H | Hydrogen | ≤ 0.015% | |
| Other | Other elements, each | ≤ 0.1% | |
| Other | Other elements, total | ≤ 0.4% | |
Mechanical minima by form
Guaranteed values differ by form, size and delivery condition; quotations confirm the specification, form, size and condition.
| Form | Condition | Rm MPa | Rp0.2 MPa | A ≥ % | Other requirements and notes |
|---|---|---|---|---|---|
| Bar and forgings | |||||
| Forgings | F-21: Solution treated | ≥ 793 (115 ksi) | ≥ 759 (110 ksi) | ≥ 15 | Also specified: Reduction of area Z ≥ 35 % Applies to forgings up to 1935 mm² (3 in.²) in cross section; larger sections by agreement. |
| Forgings | F-21: Solution treated and aged — moderate strength (set by aging temperature) | ≥ 966 (140 ksi) | 897 – 1096 | ≥ 10 | Also specified: Reduction of area Z ≥ 30 % As above |
| Forgings | F-21: Solution treated and aged — high strength (set by aging temperature) | ≥ 1172 (170 ksi) | 1104 – 1276 | ≥ 8 | Also specified: Reduction of area Z ≥ 20 % As above |
| Plate, sheet and strip | |||||
| Plate, sheet and strip | Solution treated (ST), t 0.3–0.6 mm | 825 – 1000 | 795 – 965 | ≥ 6 | Solution-treated for forming; age hardening follows forming. |
| Plate, sheet and strip | Solution treated (ST), t >0.6–2.5 mm | 825 – 1000 | 795 – 965 | ≥ 8 | As above |
Where this grade is recommended
Matched in 1 service conditions; ranks and scores computed from the condition-scoring matrix.
| Service condition | Industry | Temperature | Rank | Score |
|---|---|---|---|---|
| Airframe & lightweight | Aerospace | 200 – 400 °C | 2 / 10 | 86 |
Designations & equivalents
| Trade name(s) | Ti-15Mo-3Al-2.7Nb / Beta-21S |
Cross-references are common near-equivalents for search and shortlisting; substitution across standards requires clause-by-clause verification. All grades in one cross-reference table →
Applicable standards
2 specifications. Name the standard and its edition on the order.
Guaranteed values and required tests differ between specifications — see Mechanical minima by form for the figures per form.
Frequently asked questions
What is TB8 (β-21S)?
TB8 (β-21S) — Titanium. Oxidation-resistant β titanium — engine bay and hot fasteners
What is the maximum service temperature of TB8?
Typically about 550 °C; the practical limit depends on media, stress and design life — acceptance per the governing standard.
What is the tensile strength of TB8?
The specified minimum tensile strength is 825 MPa for the main product form. Minima for other forms and sizes are listed under "Mechanical minima by form" on this page.
Which standards cover TB8?
GB/T 3621, ASTM B381 (forgings, F-21)
Where is TB8 typically used?
Airframe & lightweight (Aerospace)
In which forms is TB8 available?
Tube, plate, strip, bar, forgings, wire and other forms — sizes and delivery condition confirmed per order, with EN 10204 3.1 / 3.2 certification.
Same series
Download PDF datasheet
This grade’s datasheet as an A4 PDF — for filing, printing or forwarding to colleagues.
Download PDF datasheetSupply & enquiry
Tube & pipeφ1 – 219 × 0.25 – 25 mm
Plate4.76 – 80 mm
Barφ8 – 300 mm
Wire & filler metalsφ0.01 – 8 mmFor this grade we can supply, against your service conditions:
- Tube, plate, strip, bar, forgings, wire and more — with size range and lead time
- Chemistry and mechanical test report (EN 10204 3.1 / 3.2)
- Like-for-like alternatives and selection advice
- Applicable standards and inspection scope
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