Seamless Titanium Gr5 Pipe
What is a Seamless Titanium Gr5 Pipe?
Seamless Titanium Gr5 Pipe (UNS R56400, Ti-6Al-4V) is the most widely used titanium alloy in the world, produced from a solid billet without a welded seam. By adding 6 % aluminum and 4 % vanadium to commercially pure titanium, Gr5 delivers roughly three times the strength of Grade 2 while retaining the alloy family's outstanding corrosion resistance.
With a tensile strength of 895 MPa minimum at only 4.43 g/cm³ density, Gr5 offers the best strength-to-weight ratio of any mainstream engineering metal. It combines this with excellent fatigue resistance, good weldability and useful service capability from cryogenic temperatures up to about 400 °C.
Manufactured to ASTM B338/B861 equivalents, Titanium Gr5 seamless pipe serves aerospace fluid systems, high-pressure offshore lines and demanding chemical duties where the extra strength of the 6-4 alloy justifies its premium over commercially pure grades.
Titanium Grade 5 (Ti-6Al-4V) vs Grade 2 vs Grade 23: Strength-Tuned Titanium
Grade 5 is the most used titanium alloy worldwide. This comparison shows when the alloyed grade displaces commercial-purity material.
| Grade | Key Chemistry / Condition | Where It Fits |
|---|---|---|
| Grade 2 (CP) | ~345 MPa, fully weldable/formed | Corrosion-led duty; best formability |
| Grade 5 (Ti-6Al-4V) | ~895 MPa tensile, 825 MPa yield | Twice-plus the strength of CP grades for aerospace, offshore and high-pressure tubulars |
| Grade 23 (ELI) | Gr5 with O ≤ 0.13 % | Extra-low interstitial version with superior fracture toughness for cryogenic and medical use |
| Grade 9 (Ti-3Al-2.5V) | ~620 MPa, better cold formability | Middle path for hydraulic and sport tubulars |
Product Specifications
Specification data for Seamless Titanium Gr5 Pipe is compiled from the governing ASTM/ASME/EN standards and our routine production records; typical values are shown where a standard leaves a limit open.
| Category | Standard / Designation |
|---|---|
| Seamless Pipe | ASTM B861 / ASME SB861 |
| Seamless & Welded Tube | ASTM B338 / ASME SB338 |
| Bars & Billet | ASTM B348 / B381 |
| UNS Designation | R56400 |
| Werkstoff Number | 3.7165 |
Size and Weight Chart
| OD (mm) | Typical Wall (mm) | Weight (kg/m) |
|---|---|---|
| 12.7 | 1.2 | 0.19 |
| 16.0 | 1.2 | 0.25 |
| 19.05 | 1.65 | 0.4 |
| 25.4 | 1.65 | 0.55 |
| 31.75 | 2.0 | 0.83 |
| 38.1 | 2.0 | 1.0 |
| 50.8 | 2.5 | 1.68 |
| 63.5 | 3.0 | 2.53 |
| 76.2 | 3.0 | 3.06 |
| 101.6 | 4.0 | 5.43 |
The table lists typical production sizes with a common wall for each diameter; the full dimensional programme of the governing standard is available, and intermediate diameters, walls and lengths are cut to order.
Chemical Composition
| Element | Min (%) | Max (%) |
|---|---|---|
| Titanium (Ti) | Balance | — |
| Aluminum (Al) | 5.5 | 6.75 |
| Vanadium (V) | 3.5 | 4.5 |
| Iron (Fe) | — | 0.40 |
| Oxygen (O) | — | 0.20 |
| Carbon (C) | — | 0.08 |
| Nitrogen (N) | — | 0.05 |
| Hydrogen (H) | — | 0.015 |
Mechanical Properties
| Property | Value |
|---|---|
| Tensile Strength, min | 895 MPa (130 ksi) |
| Yield Strength (0.2 % offset), min | 828 MPa (120 ksi) |
| Elongation in 2 in. / 50 mm, min | 10 % |
| Hardness (typical) | ≈ 334 HBW |
| Condition | Annealed per ASTM B338/B861 |
Physical Properties
| Property | Value |
|---|---|
| Density | 4.43 g/cm³ |
| Melting Range | 1604 – 1660 °C |
| Elastic Modulus | 114 GPa |
| Coefficient of Thermal Expansion (20–100 °C) | 8.6 µm/m·°C |
| Thermal Conductivity (at 20 °C) | 6.7 W/m·K |
| Electrical Resistivity | 170 µΩ·cm |
| Specific Heat Capacity | 526 J/kg·K |
Equivalent Grades
| Standard System | Designation |
|---|---|
| UNS | R56400 |
| Werkstoff Nr. | 3.7165 |
| DIN | TiAl6V4 |
| ASTM | B338 / B861 / B348 |
Why Grade 5 Sets the Strength Benchmark
The 6 % aluminium / 4 % vanadium addition transforms titanium from a corrosion metal into a structural one. Alpha-phase aluminium and beta-phase vanadium stabilization produce a two-phase microstructure with roughly 895 MPa tensile strength — comparable to many heat-treated steels at less than 60 % of their density — together with useful fatigue performance and service capability to about 400 °C. Aerospace hydraulic lines, engine components, offshore riser components and high-performance automotive tubulars all build on this combination.
Our Grade 5 seamless tube follows the aerospace route: double vacuum arc remelting, ultrasonically inspected forging, jacketed hot extrusion, cold pilgering and vacuum annealing, with mechanical, microstructural and NDT certification per ASTM B338/B861. Where fracture toughness at low temperature governs, we also supply Grade 23 (ELI) from the same production line.
Manufacturing Process
Our seamless production route for Seamless Titanium Gr5 Pipe follows these documented stages:
- Sponge Consolidation & Double Melting: High-purity titanium sponge is compacted with alloying additions and double- or triple-melted in vacuum consumable-arc furnaces for homogeneity.
- Billet Forging: Ingots are forged to extrusion rounds with ultrasonic inspection for internal defects.
- Hot Extrusion / Rolling: Billets, jacketed to protect against oxygen pickup, are hot-extruded or hot-rolled into tube shells.
- Cold Pilgering: Cold pilgering produces the final precision wall with excellent surface finish.
- Vacuum Annealing: Final annealing under vacuum (typically 650-800 °C) preserves the low interstitial content and bright surface.
- Testing & Certification: Tensile, hardness, flare/flattening, eddy-current and ultrasonic testing confirm conformity to ASTM B338/B861.
Surface Finish Options
- Vacuum-Annealed Bright: Standard condition; oxygen-free reflective surface.
- Pickled: For weld-prep and chemical service.
- Precision Ground / Polished: For instrumentation and specialty equipment.
Dimensional Tolerances
Delivered dimensions are verified against the tolerances below; tighter tolerances can be negotiated for instrumentation and precision applications.
| Dimension | Tolerance |
|---|---|
| OD, tube ≤ 25.4 mm (cold worked) | ± 0.10 mm |
| OD, tube 25.4 – 38.1 mm | ± 0.15 mm |
| OD, tube 38.1 – 50.8 mm | ± 0.20 mm |
| OD, hot-finished pipe ≥ 50.8 mm | ± 1 % of OD |
| Wall thickness | - 12.5 % under-tolerance (min-wall basis) |
| Straightness | ≤ 1 mm per metre |
| Cut length | + 10 / - 0 mm (fixed lengths) |
Common Industrial Applications
Because of its characteristic property profile, Seamless Titanium Gr5 Pipe is specified in the following industries and services:
- Aerospace Fluid Systems: Hydraulic, fuel and pneumatic piping in airframes and engines — the classic Ti-6Al-4V duty.
- Deep-Water Offshore Riser Components: High-pressure, low-weight corrosion service where steel would fail or sink the platform economics.
- High-Pressure Chemical Lines: Piping needing both aggressive-media resistance and pressure capability beyond Gr2.
- Motorsport & Performance Vehicles: Exhaust and coolant lines exploiting the strength-to-weight advantage.
- Desalination High-Pressure Systems: Pump discharge and high-pressure lines where Gr2 wall would be too thick.
- Cryogenic Applications: ELI-condition lines for LNG and aerospace cryogenic systems.
Quality Assurance, Testing and Documentation
Every length of Seamless Titanium Gr5 Pipe passes through a documented quality-control chain before dispatch:
- Material Certification: EN 10204 3.1 mill test certificates are issued for every heat; 3.2 certification with third-party witness (TUV, SGS, BV) is available on request.
- Chemical & Mechanical Testing: Heat-level chemical analysis plus tensile, hardness and, where applicable, flattening, flaring and reverse-flattening tests per the governing standard.
- Non-Destructive Examination: 100 % eddy-current or ultrasonic testing and hydrostatic or pneumatic pressure testing in line with the standard's supplementary requirements.
- Dimensional & Visual Inspection: Full OD, wall thickness, ovality and length verification with visual surface inspection after pickling or finishing.
- Traceability & Marking: Heat numbers stenciled or banded on every length, maintaining complete melt-to-pipe traceability.
Export and Packaging
Pipes are bundled with steel strapping and fitted with plastic or steel end caps, then packed in seaworthy wooden cases or crates and secured in containers for long-distance ocean freight. Standard export documentation — commercial invoice, packing list, certificate of origin, mill test certificates and, where required, third-party inspection reports — accompanies every shipment. Container-load and bulk project orders receive priority production slots and consolidated shipping documentation.
Frequently Asked Questions
Q1. Why choose Gr5 over Gr2 for piping?
A: Gr5 provides roughly 2.6 times the strength, allowing much thinner walls and lighter systems at equal pressure rating. For ordinary seawater or chemical duty, Gr2 is sufficient and more economical; Gr5 is selected when weight or pressure dominates.
Q2. Is Gr5 as corrosion resistant as Gr2?
A: In seawater and oxidizing media, essentially yes. In strongly reducing acids, Gr5 is slightly less resistant than pure titanium — Gr7 with palladium is the correct choice for those environments.
Q3. Can Gr5 pipe be welded?
A: Yes, with TIG or plasma welding under strict inert shielding. Weld strength matches the annealed base metal; hot cracking is not a concern with proper practice.
Q4. What is the maximum service temperature for Gr5 pipe?
A: Around 400 °C for pressure-retaining service; short excursions slightly higher are acceptable, but oxygen pickup above 600 °C embrittles the alloy.
Ready to Request a Quotation?
Send us your size range, wall thickness/schedule, standard and quantity for Seamless Titanium Gr5 Pipe, and our engineering team will respond with a detailed technical and commercial offer within 24 hours. Custom sizes, third-party inspection and full export documentation are part of our standard service.
