What Grade 9 is
Grade 9 (UNS R56320, Ti-3Al-2.5V) is a near-alpha alloy containing 2.5–3.5% aluminium and 2.0–3.0% vanadium. It was developed specifically for tubing, and that origin still shapes how it is used: it is a tube grade that also happens to be available in bar and wire.
The useful way to place it is between Grade 2 and Grade 5. It offers about 80% more minimum tensile strength than Grade 2, which lets a designer drop wall thickness and save weight, while remaining substantially more weldable and more cold-workable than Grade 5. Grade 5 bicycle tubing exists, but it is harder to form and join, which is why Grade 9 dominates the field.
Chemical composition
| Element | Requirement |
|---|---|
| Aluminium, Al | 2.5 – 3.5 |
| Vanadium, V | 2.0 – 3.0 |
| Iron, Fe | 0.25 max |
| Oxygen, O | 0.15 max |
| Carbon, C | 0.08 max |
| Nitrogen, N | 0.03 max |
| Hydrogen, H | 0.015 max |
| Titanium, Ti | Balance |
Composition limits and mechanical values below are the published requirements of the referenced ASTM specification. They state what the standard requires — they are not the measured result of any particular heat or lot, and they are not a guarantee of what a given order will return.
Mechanical properties and weldability
| Property | Minimum value |
|---|---|
| Tensile strength | 620 MPa (90 ksi) |
| Yield strength, 0.2% offset | 483 MPa (70 ksi) |
| Elongation in 2 in / 50 mm | 15% |
| Typical density | 4.48 g/cm³ (reference value) |
Cold-worked Grade 9 tube is commonly supplied in stress-relieved condition at higher strength than the annealed minimums. The condition and certificate requested should be stated on the enquiry.
The weldability is the property that sells it. Grade 9 welds cleanly with normal titanium shielding discipline, and because its alloy content is low the heat-affected zone retains useful ductility rather than becoming brittle. That combination — a welded joint that survives the forming and the fatigue duty afterwards — is what a frame builder is actually buying.
Grade 9 vs Grade 5
| Factor | Grade 9 | Grade 5 |
|---|---|---|
| Tensile strength, min annealed | 620 MPa | 895 MPa |
| Yield strength, min annealed | 483 MPa | 828 MPa |
| Elongation, min | 15% | 10% |
| Weldability | Excellent — the grade's defining advantage | Good, with more care required |
| Cold forming into tube | Far easier | Difficult |
| Heat-treatable to higher strength | Limited response | Yes — STA raises strength substantially |
| Typical use | Welded tube structures, frames, hydraulic line | Highly loaded machined parts, fasteners, aerospace |
The reverse direction of that table is covered in detail on the Grade 5 page, where strength rather than formability is the deciding factor.
Supply forms
- Seamless tube — the principal form; see tube & pipe. Hydraulic-quality cold-worked tube is the largest use.
- Round bar — quoted to ASTM B348 for machined components. See bar & rod.
- Wire — used for spokes and small structural elements; see wire.
- Square and rectangular tube — occasional structural use; see the tube page for available forms.
Availability, size range and lead time for a specific grade and form are confirmed in the quotation — please contact us for confirmation.
Where Grade 9 is used
Bicycle frames
Cold-drawn seamless tube, welded and formed — the reason the grade was developed.
Tube & pipe →
Sporting goods
Golf shafts, ski poles and similar weight-critical tubular products.
Tube & pipe →
Eyewear
Wire and small section material for frames and hinges.
Wire →
Hydraulic & pneumatic line
Aircraft-grade hydraulic tubing taking advantage of strength-to-weight.
Tube & pipe →
Automotive
Exhaust and structural tube where weight justifies titanium.
Tube & pipe →
Marine hardware
Seawater-resistant structural tube and fittings.
Marine service →
Building a tube structure? Send OD, wall, length, condition and quantity — Grade 9 quotes come back most accurately with the wall schedule included.
WhatsAppSend your specificationRequest Grade 9 titanium
Tell us the tube schedule — OD, wall thickness, length and whether annealed or cold-worked and stress-relieved — plus quantity and application.
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