Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy vs Titanium Grade 2: Commercially Pure CP Ti for Corrosion Service
Side-by-side engineering comparison of Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy (ASTM B265/B348 / AMS 4911) and Titanium Grade 2: Commercially Pure CP Ti for Corrosion Service (ASTM B265/B348). Compare mechanical properties, chemical composition, density, yield strength, international equivalents, and typical applications to select the right material for your project.
Quick Verdict
Choose Ti-6Al-4V (Grade 5) when maximum strength-to-weight ratio is required — aerospace structures, medical implants, and high-stress components where its 880 MPa yield (3.2× Grade 2's 275 MPa) justifies the 2-3× cost premium and harder fabrication. Choose Grade 2 commercially pure titanium when corrosion resistance is the primary requirement and loads are moderate — chemical processing heat exchangers, marine piping, and medical device housings benefit from Grade 2's superior formability, weldability, and lower cost....
Formability, weldability, and lower cost
Maximum strength-to-weight ratio
Quick Comparison
| Property | Ti-6Al-4V (Grade 5): The | Titanium Grade 2: Commerc |
|---|---|---|
| Standard | ASTM B265/B348 / AMS 4911 | ASTM B265/B348 |
| Category | Titanium Alloy | Titanium Alloy |
| Density | 4.43 g/cm³ | 4.51 g/cm³ |
| Yield Strength | 880 MPa (128 ksi) annealed | 275 MPa (40 ksi) annealed |
| Tensile Strength | 950 MPa (138 ksi) annealed | 345 MPa (50 ksi) annealed |
| Key Applications | <a href="https://ykwiki.com/materials/ti-6al-4v/">Ti-6Al-4V</a> (Grade 5) accounts for over 50% of global titanium usage... | Titanium Grade 2 is commercially pure (unalloyed) titanium with 99.2% minimum Ti content. It provides the best combinati... |
International Equivalents
| Ti-6Al-4V (Grade 5): Equivalents | Titanium Grade 2: Co Equivalents |
|---|---|
| EN 3.7165 | EN 3.7035 |
| BT6 | BT1-0 |
| JIS TAP6400 | JIS TP340 |
| TC4 | TA2 |
| ISO Ti-6Al-4V | ISO Ti Grade 2 |
Price & Cost Comparison
Approximate raw-material price per kg as of 2026. Fabricated part cost depends on machining time, section size, and order quantity — a 2-5× material price gap often narrows once total part cost is weighted.
| Ti-6Al-4V (Grade 5): The | Titanium Grade 2: Commerc | |
|---|---|---|
| Raw Material / kg | $55–90/kg (bar) | $30–45/kg (bar) |
| Relative Cost | Ti-6Al-4V (Grade 5) typically costs 60–100% more than Grade 2 per kg. | |
Both grades carry titanium's enormous cost premium over steel (~10–20× A36). Grade 5's alloying (6% Al, 4% V) and higher processing cost push it 1.6–2× above Grade 2. On a chemical-plant heat exchanger vs an aerospace bracket, the logic flips: Grade 2 builds on cost-effective corrosion immunity, while Grade 5's 880 MPa yield (3.2× Grade 2) earns its premium through weight savings in specialty hardware.
Grade 5's premium buys 880 MPa yield at 4.43 g/cm³ — the highest strength-to-weight of commercial titanium. For aerospace structural parts, medical implants, and racing components, the 3.2× strength advantage and 350°C service capability justify the cost.
Grade 2's lower price and superior formability, weldability, and corrosion immunity make it the economic choice for chemical processing, marine, and heat-transfer equipment — where strength is secondary to chloride resistance and fabricability. It delivers titanium's corrosion benefits without Grade 5's alloy premium.
How to Choose
| Choose Ti-6Al-4V (Grade 5): The when... | Ti-6Al-4V (Grade 5) delivers 880 MPa yield — 3.2× Grade 2's 275 MPa — making it the standard for aerospace and medical implants. |
| Choose Titanium Grade 2: Commerc when... | Grade 2 commercially pure titanium offers superior formability, weldability, and corrosion resistance at 2-3× lower cost. |
Decision Checklist: Which Is Right for You?
| Criterion | Ti-6Al-4V (Grade 5): | Titanium Grade 2: Co |
|---|---|---|
| Formability, Weldability, And Lower Cost | ✓ | |
| Maximum Strength-To-Weight Ratio | ✓ | |
| Higher yield strength | ✓ | |
| Strength requirement — Grade 5 provides 3.2× the yield strength of Gra... | ✓ | |
| Formability — Grade 2 is easily cold-formed (bend radius 2-3T) and dee... | ✓ | |
| Weldability — both weld with inert-gas shielding (GTAW/PAW); Grade 2 i... | ✓ |
Selection Guide
Choose Ti-6Al-4V (Grade 5) when maximum strength-to-weight ratio is required — aerospace structures, medical implants, and high-stress components where its 880 MPa yield (3.2× Grade 2's 275 MPa) justifies the 2-3× cost premium and harder fabrication. Choose Grade 2 commercially pure titanium when corrosion resistance is the primary requirement and loads are moderate — chemical processing heat exchangers, marine piping, and medical device housings benefit from Grade 2's superior formability, weldability, and lower cost. Grade 5 for strength; Grade 2 for corrosion and fabrication.
Key Decision Factors
- Strength requirement — Grade 5 provides 3.2× the yield strength of Grade 2 (880 MPa vs 275 MPa); if loads are moderate, Grade 2 is sufficient and cheaper
- Formability — Grade 2 is easily cold-formed (bend radius 2-3T) and deep-drawn; Grade 5 has limited cold formability and typically requires hot forming at 700-850°C
- Weldability — both weld with inert-gas shielding (GTAW/PAW); Grade 2 is more forgiving, Grade 5 requires precise joint prep and shielding to avoid oxygen/nitrogen embrittlement
- Cost — Grade 5 costs 2-3× more than Grade 2 due to vanadium and aluminum additions and the more complex alpha-beta processing required
When to Use Each
Use Ti-6Al-4V (Grade 5): for:
Ti-6Al-4V's 880 MPa yield at 4.43 g/cm³ provides 50% higher specific strength than 7075-T6 aluminum — standard for aircraft engine disks, landing gear, and fasteners where weight savings directly reduce fuel burn.
Grade 5's high strength and biocompatibility make it the standard for hip stems, bone plates, screws, and dental implants. Its alpha-beta microstructure provides the fatigue resistance required for millions of load cycles.
Ti-6Al-4V is used for bicycle frames, golf club heads, firearm suppressors, and military armor where maximum strength at minimum weight justifies the 10-20× cost premium over steel.
Use Titanium Grade 2: Co for:
Grade 2's superior corrosion resistance (uniform TiO2 film without alloying element depletion) and formability make it standard for shell-and-tube exchangers handling chlorides, seawater, and oxidizing acids.
Grade 2 resists seawater corrosion at high flow velocities (no pitting, no SCC), and its lower strength is acceptable in low-pressure piping systems. Easier to bend and weld than Grade 5.
Grade 2's formability enables deep-drawn medical housings and complex-shaped surgical instruments. Its lower strength is adequate for non-load-bearing devices, and cost is 40-50% less than Grade 5.
Frequently Asked Questions
What is the main difference between Ti-6Al-4V (Grade 5): The Workh and Titanium Grade 2: Commercially?
Ti-6Al-4V (Grade 5): The Workhorse Titanium Alloy (ASTM B265/B348 / AMS 4911) provides 880 MPa (128 ksi) annealed yield strength at 4.43 g/cm³ density, while Titanium Grade 2: Commercially Pure CP Ti for Corrosion Service (ASTM B265/B348) delivers 275 MPa (40 ksi) annealed at 4.51 g/cm³. The choice depends on whether your application prioritizes formability, weldability, and lower cost or maximum strength-to-weight ratio.
Can Ti-6Al-4V (Grade 5): The Workh be substituted for Titanium Grade 2: Commercially?
In many applications, these materials can be cross-referenced, but direct substitution should always be verified against specific project specifications, especially for formability, weldability, and lower cost, maximum strength-to-weight ratio, and operating environment. Consult your engineer of record.
Can Grade 2 titanium be heat-treated to increase strength?
No. Commercially pure titanium (Grades 1-4) is a single-phase alpha alloy that cannot be strengthened by heat treatment — strength comes only from grain size, oxygen/iron interstitial content, and cold work. To achieve strength above ~480 MPa (Grade 4 maximum), you must switch to an alloyed grade like Ti-6Al-4V (Grade 5, 880 MPa) or beta alloys like Ti-15V-3Cr-3Al-3Sn (Grade 21).
Is Grade 5 or Grade 2 more corrosion resistant?
Grade 2 is generally more corrosion resistant in aggressive media. Both rely on the self-healing TiO2 passive film, but Grade 5's aluminum and vanadium alloying elements can create micro-galvanic cells and slightly reduce resistance in reducing acids (HCl, H2SO4). In oxidizing environments (seawater, nitric acid, wet chlorine), both perform excellently. For severe reducing-acid service, consider Ti-Pd (Grade 7) or Ti-Ru (Grade 26) grades.
Why is Ti-6Al-4V so much harder to machine than Grade 2?
Two reasons: (1) Grade 5's higher strength (880 MPa) means higher cutting forces and faster tool wear; (2) titanium's low thermal conductivity (7 W/m·K) concentrates heat at the tool tip, and Grade 5's higher hardness exacerbates this. Use sharp carbide (C2 grade), low cutting speeds (30-60 m/min vs 150+ for steel), high feed rates, and copious high-pressure coolant. Grade 2 machines somewhat better (lower strength) but still requires the same 'titanium machining rule' of 10× coolant flow and 1/3 cutting speed vs steel.
Can Ti-6Al-4V be 3D printed?
Yes — Ti-6Al-4V is the most commonly 3D-printed titanium alloy, using powder bed fusion (SLM/EBM). The process produces near-forged strength (900-1100 MPa) with complex geometries impossible by machining. Applications include medical implants with lattice structures, aerospace brackets, and custom tooling. Grade 2 CP titanium powder is also available for printing but is less common. Post-print HIP (hot isostatic pressing) is typically required to close internal porosity for fatigue-critical parts.
Which grade is better for a medical implant?
It depends on the load. For load-bearing implants (hip stems, knee components, bone plates, spinal cages), Ti-6Al-4V Grade 5 is the standard — its 880 MPa yield withstands millions of load cycles. For non-load-bearing implants (pacemaker housings, surgical instruments, dental crowns), Grade 2 is preferred for its better formability, lower cost, and slightly superior biocompatibility (no vanadium, which has raised long-term toxicity concerns in some studies). Both are ISO 5832 compliant for implant use.