Ti Grade 2 (CP) vs Ti-6Al-4V (Grade 5)
Both are titanium, but they sit at opposite ends of the property spectrum: Ti Grade 2 is commercially pure (CP) titanium prized for formability and corrosion resistance, while Ti-6Al-4V (Grade 5) is the workhorse alpha-beta alloy you reach for when you need real structural strength.
The verdict
Choose Ti Grade 2 (CP) when corrosion resistance, weldability and cold formability matter more than strength — think chemical vessels, heat exchangers and tubing. Choose Ti-6Al-4V (Grade 5) when you need high strength-to-weight for load-bearing or fatigue-critical parts — aerospace structures, fasteners and orthopedic implants. In short: Grade 2 for corrosion and forming, Grade 5 for structural strength.
Side-by-side data
| Property | Ti Grade 2 (CP) | Ti-6Al-4V (Grade 5) |
|---|---|---|
| Category | Titanium | Titanium |
| Density (g/cm³) | 4.51 | 4.43 |
| Tensile strength (MPa) | 485 | 1000 |
| Yield strength (MPa) | 380 | 910 |
| Elongation (%) | 20 | 14 |
| Hardness | 200 HB | 36 HRC |
| Max service temp (°C) | 425 | 400 |
| Machinability | ●●●●● | ●●●●● |
| Corrosion resistance | ●●●●● | ●●●●● |
| Relative cost | ●●●●● | ●●●●● |
| Thermal cond. (W/m·K) | 17 | 6.7 |
| Typically used for | Corrosion-critical, formable titanium | Aerospace & medical — best strength-to-weight |
Which should you choose?
Choose Ti Grade 2 (CP) if…
- You need maximum weldability — it welds readily with no post-weld heat treatment and keeps full strength in the joint
- The part will be cold-formed, deep-drawn, bent or spun, where Grade 5's low ductility would crack
- Corrosion resistance in seawater, chlorides or acids is the primary driver, not load capacity
- You're building tubing, plate heat exchangers, pressure vessels, or chemical/marine hardware
- Cost and easier machining matter more than squeezing out peak strength
Choose Ti-6Al-4V (Grade 5) if…
- The part is load-bearing or fatigue-critical and needs the best strength-to-weight ratio
- You're designing aerospace structures, brackets, shafts, or high-strength fasteners
- It's an orthopedic or dental implant where strength plus biocompatibility are both required
- Service temperatures run higher (useful to ~315-400°C), beyond CP titanium's comfort zone
- You can heat-treat (solution + age) to tune mechanical properties for the application
Key differences that matter
- Strength-to-weight is the decisive split: Grade 5 is roughly two to three times stronger than Grade 2 at nearly identical density, which is why it dominates structural and aerospace use.
- Formability and ductility favor Grade 2 — it cold-forms and deep-draws well, while Grade 5 is far less ductile and is usually formed hot or machined to shape.
- Both resist corrosion superbly via the same passive TiO2 layer; Grade 2 is marginally better in some reducing acids, but for most service they are equivalent, so corrosion rarely breaks the tie alone.
- Weldability favors Grade 2: ductile joints with no post-weld treatment, whereas Grade 5 welds can be brittle in the heat-affected zone and often need careful procedure or PWHT.
- Machinability and cost favor Grade 2; Grade 5 is harder on tooling and pricier, but only it can be strengthened by heat treatment. Both anodize identically, so surface finish is not a differentiator.
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Open the Material SelectorGet a Quote →Frequently asked questions
Is Ti Grade 2 (CP) stronger than Ti-6Al-4V (Grade 5)?
No. Grade 5 is substantially stronger — on the order of two to three times the yield and tensile strength of Grade 2 — which is the main reason to pick it. Grade 2 trades that strength for better ductility, weldability and forming behavior.
Which one is cheaper?
Grade 2 is generally cheaper, both in raw material and in fabrication, because it machines and welds more easily and needs no heat treatment. Grade 5 costs more due to alloying (aluminum and vanadium), tougher machining, and optional heat-treat steps.
Can I weld both grades?
Both are weldable with GTAW/TIG under proper inert-gas shielding. Grade 2 is easier and yields ductile joints with no post-weld heat treatment. Grade 5 can weld but the heat-affected zone tends to be harder and more brittle, so it demands careful procedure control and is welded less often.
Do they corrode differently?
Not much in practice. Both form the same protective titanium-oxide film and excel in seawater, chlorides and many acids. Grade 2 has a slight edge in certain reducing environments, but for the vast majority of applications their corrosion performance is effectively equal.
Can both be anodized and machined?
Yes to anodizing — both take type-2 and color (type-3) titanium anodizing identically. For machining, Grade 2 is noticeably more forgiving on tools and speeds; Grade 5 is machinable but work-hardens and runs hotter, so it needs sharp tooling, rigid setups and good coolant.
Property values are typical/nominal figures for early-stage guidance only and vary by temper, grade, supplier and heat treatment. Confirm critical specifications against a certified datasheet or with an mfgiq engineer before production.