Choosing between Grade 5 (Ti-6Al-4V) and Grade 2 (Commercially Pure Titanium) square tubes significantly impacts performance, cost, and application suitability. This guide provides a detailed comparison to help engineers, manufacturers, and procurement specialists make informed decisions.
Key Takeaways:
✔ Grade 5 = Higher strength, aerospace/medical use
✔ Grade 2 = Better corrosion resistance, cost-effective
✔ Critical factors: Strength, weldability, cost, industry standards
1. Material Composition & Properties
| Property | Grade 2 (CP Titanium) | Grade 5 (Ti-6Al-4V) |
|---|---|---|
| Composition | 99%+ Titanium | 90% Ti, 6% Al, 4% V |
| Tensile Strength | 345 MPa | 895 MPa |
| Yield Strength | 275 MPa | 828 MPa |
| Elongation (%) | 20% | 10% |
| Density (g/cm³) | 4.5 | 4.43 |
| Corrosion Resistance | Excellent | Good (but less than Gr 2) |
| Biocompatibility | Yes | Yes (medical implants) |
Key Differences:
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Strength: Grade 5 is ~3x stronger than Grade 2.
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Ductility: Grade 2 is more formable and weldable.
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Temperature Resistance: Grade 5 performs better in high-temp applications.
2. Applications: Which Grade Should You Choose?
Best for Grade 2 Titanium Square Tube:
✅ Chemical Processing (acid-resistant piping)
✅ Marine & Offshore (seawater corrosion resistance)
✅ Architectural (lightweight, aesthetic structures)
✅ Medical (non-load-bearing implants)
Best for Grade 5 Titanium Square Tube:
✅ Aerospace (airframe components, landing gear)
✅ Medical Implants (hip joints, bone screws)
✅ High-Stress Automotive (racing components)
✅ Military & Defense (armor, ballistic protection)
3. Machining & Fabrication Comparison
| Factor | Grade 2 | Grade 5 |
|---|---|---|
| Machinability | Easy | Difficult (harder material) |
| Weldability | Excellent | Good (requires expertise) |
| Formability | High | Low (prone to cracking) |
| Heat Treatment | Not needed | Can be heat-treated for extra strength |
Fabrication Tips:
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Grade 2: Easier to cut, bend, and weld—ideal for custom fabrications.
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Grade 5: Requires specialized tooling (carbide tools recommended).
4. Cost Comparison & Procurement Tips
Price Factors:
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Grade 5 is ~2–3x more expensive than Grade 2 (due to alloying elements).
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Lead times may vary—Grade 5 often requires custom orders.
How to Choose the Right Supplier?
✔ Check ASTM certifications (B338 for Grade 2, B348 for Grade 5)
✔ Request Mill Test Reports (MTRs) for material verification
✔ Compare prices per kg (varies by thickness & quantity)
5. FAQs – Grade 5 vs. Grade 2 Titanium Square Tube
Q1: Can Grade 2 replace Grade 5 in high-stress applications?
No. Grade 2 lacks the strength for aerospace or load-bearing medical uses.
Q2: Which grade is better for welding?
Grade 2 is easier to weld without cracking.
Q3: Does Grade 5 corrode faster than Grade 2?
Yes, slightly. Grade 2 has superior corrosion resistance in harsh environments.
Conclusion: Which Grade is Right for You?
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Choose Grade 2 if: You need cost-effective, corrosion-resistant, easy-to-fabricate tubing.
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Choose Grade 5 if: You require maximum strength, aerospace/medical compliance, or high-temperature performance.
Need help sourcing titanium square tubes? Work with certified suppliers who provide material certifications and custom sizes. Email:linhui@lhtitanium.com
