Gr2 vs Gr5 Titanium: Key Differences Explained
Jan 15, 2026
Understanding the Two Grades
Grade 2 (Gr2) is the most widely used commercially pure titanium, containing at least 99% titanium with controlled oxygen, iron, and carbon. Grade 5 (Gr5), also known as Ti-6Al-4V, is an alpha-beta alloy with about 6% aluminum and 4% vanadium and is the most widely used titanium alloy overall. Both are recognized under ASTM B348 for bars and billets and ASTM B265 for sheet and plate.
Composition at a Glance
| Element | Gr2 | Gr5 |
|---|---|---|
| Titanium | Balance (≥ 99%) | Balance (~90%) |
| Aluminum | - | 5.5–6.75% |
| Vanadium | - | 3.5–4.5% |
| Oxygen (max) | 0.25% | 0.20% |
| Iron (max) | 0.30% | 0.40% |
| Carbon (max) | 0.08% | 0.10% |
Density: Corrected Values
A common error in online material tables is swapping the density values. The correct figures are: Gr2 ≈ 4.51 g/cm³ and Gr5 ≈ 4.43 g/cm³. Although the difference is small, it matters in aerospace and medical weight calculations, where the lighter alloy helps offset higher strength requirements.
Mechanical Properties
| Property | Gr2 | Gr5 |
|---|---|---|
| Tensile strength (min) | 345 MPa | 895 MPa |
| Yield strength 0.2% (min) | 275 MPa | 825 MPa |
| Elongation (min) | 20% | 10% |
| Typical hardness | 160–200 HV | 330–380 HV |
Gr5 is roughly two to three times stronger than Gr2, at the cost of reduced ductility. Gr2 retains excellent formability and impact toughness.
Corrosion Resistance
Both grades form a protective oxide film. Gr2, being purer, generally offers the best resistance in seawater, chlorides, and mildly reducing media, which is why it dominates chemical processing and marine piping. Gr5 performs well in most environments but may require anodizing or coatings for prolonged aggressive chloride exposure. In highly reducing or crevice conditions, palladium-bearing grades such as Gr7 should be considered instead of either grade.
Machining, Welding, and Forming
Gr2 cuts and welds more easily: TIG and MIG welding with proper argon shielding give sound joints, and cold forming is straightforward. Gr5 needs sharper tooling, lower speeds, and controlled heat input; welding typically uses GTAW with matching filler and often post-weld heat treatment. These differences raise the fabrication cost of Gr5, which buyers should include in total-cost comparisons.
Applications
Gr2 is specified for heat exchanger tubes, piping, tanks, desalination plants, and architectural structures. Gr5 is the default for aerospace structural parts, medical implants, high-performance fasteners, and racing components where strength-to-weight ratio and fatigue resistance dominate.
Selection Checklist
Corrosion service in seawater or chemicals: Gr2 (or Gr7 for crevice/reducing conditions).
High strength and fatigue: Gr5.
Deep drawing or severe forming: Gr2.
Elevated-temperature structural service above 300°C: evaluate Gr5 or creep-resistant grades.
Budget-sensitive, moderate loading: Gr2 offers lower material and fabrication cost.
Frequently Asked Questions
Which titanium grade is stronger, Gr2 or Gr5?
Gr5 is significantly stronger, with a minimum tensile strength of 895 MPa versus 345 MPa for Gr2, making it about two to three times stronger.
What is the density difference between Gr2 and Gr5?
Gr2 has a density of about 4.51 g/cm³ and Gr5 about 4.43 g/cm³. The values are often reversed in unreliable sources; verify against mill certificates.
Is Gr2 or Gr5 better for seawater?
Gr2 generally offers superior natural corrosion resistance in seawater and is widely used in desalination and offshore systems. Gr5 is chosen when high strength is also required.
Can Gr5 be welded like Gr2?
Gr5 can be welded, but it requires controlled GTAW or electron beam procedures, proper shielding, and often post-weld heat treatment, while Gr2 welds more easily.
Why is Gr5 more expensive than Gr2?
Gr5 costs more because of alloying elements, stricter processing, and higher machining and welding costs, though its strength may reduce part weight and improve lifecycle value.
Which grade should I choose for medical implants?
For load-bearing implants, Gr5 or Gr23 (Ti-6Al-4V ELI per ASTM F136) is standard. Gr2 is used mainly for low-stress implant components and surgical instruments.
