Search

Grade 5 (Ti-6Al-4V) vs Grade 23 (Ti-6Al-4V ELI): Complete Comparison

Compare Ti-6Al-4V (Grade 5) vs Ti-6Al-4V ELI (Grade 23) titanium alloys. Mechanical properties, oxygen content, fracture toughness, cost difference, and application recommendations for CNC machining.

Grade 5 (Ti-6Al-4V)vsGrade 23 (Ti-6Al-4V ELI)

Quick Answer

Choose Grade 5 (Ti-6Al-4V) for general aerospace and industrial applications where its higher strength (950 MPa vs 860 MPa) and lower cost advantage matter. Choose Grade 23 (Ti-6Al-4V ELI) for medical implants, surgical instruments, and low-temperature applications requiring enhanced fracture toughness. Grade 23 costs 15-25% more.

Quick Answer

Choose Grade 5 (Ti-6Al-4V) for general aerospace and industrial applications where higher strength (950 MPa) and lower cost are priorities. Choose Grade 23 (Ti-6Al-4V ELI) for medical implants requiring enhanced fracture toughness and biocompatibility per ASTM F136. Grade 23 costs 15-25% more.

Side-by-Side Comparison

Property Grade 5 (Ti-6Al-4V) Grade 23 (Ti-6Al-4V ELI) Winner
Ultimate Tensile Strength 950 MPa (min) 860 MPa (min) Grade 5
Yield Strength (0.2%) 880 MPa (min) 795 MPa (min) Grade 5
Elongation 14% (min) 10% (min) Grade 5
Hardness (Annealed) 36 HRC 32 HRC Grade 5
Oxygen Content (max) 0.20% 0.13% Grade 23
Fracture Toughness (KIC) ~85 MPa√m ~100 MPa√m Grade 23
Fatigue Strength ~500 MPa ~500 MPa Tie
Modulus of Elasticity 114 GPa 114 GPa Tie
Density 4.43 g/cm³ 4.43 g/cm³ Tie
Biocompatibility Standard Excellent (ASTM F136) Grade 23

Mechanical Properties

Grade 5 Advantages

  • 16% higher ultimate tensile strength (950 vs 860 MPa)
  • 11% higher yield strength (880 vs 795 MPa)
  • Slightly harder (36 vs 32 HRC)

Grade 23 Advantages

  • 35% lower oxygen content (0.13% vs 0.20%) — the defining difference
  • ~18% higher fracture toughness (~100 vs ~85 MPa√m)
  • Certified biocompatibility per ASTM F136 for surgical implants

Manufacturability

Aspect Grade 5 Grade 23
Machinability Good (requires carbide tools) Similar to Grade 5
Weldability Good Slightly better (lower interstitials)
Formability Good Excellent (higher ductility)
Heat Treatment Stress relief at 700°C Same parameters

Cost Analysis

Factor Grade 5 Grade 23
Raw Material Cost Baseline +15-25%
Availability Excellent (common stock) Good (medical distributors)
Machining Cost Similar Similar
Certification Cost Standard +ASTM F136 testing

Lead Time Comparison

  • Grade 5: 1-2 weeks for common sizes (bar, plate, sheet)
  • Grade 23: 2-4 weeks (requires medical-grade certification)
  • Custom sizes: 4-8 weeks for both grades

Choose Grade 5 When

  • Aerospace structural components
  • General industrial parts
  • High-temperature applications (up to 400°C)
  • Cost-sensitive projects
  • Non-medical applications

Choose Grade 23 When

  • Medical implants (requires ASTM F136)
  • Surgical instruments
  • Low-temperature/cryogenic applications (to -253°C)
  • Fracture-critical components
  • Regulatory-compliant medical devices

Selection Decision Framework

If medical implant → Grade 23 (ASTM F136)
If aerospace structural → Grade 5
If cost-sensitive → Grade 5
If maximum fracture toughness → Grade 23
If temperature < -50°C → Grade 23
If temperature > 300°C → Grade 5

FAQ

Which grade is better for CNC machining? Both machine similarly. Grade 5 is slightly harder, but cutting parameters are nearly identical.

Can Grade 23 be anodized? Yes. Both grades anodize similarly. Color anodizing works on both.

Are material certifications included? Yes, for both grades — mill test reports (MTRs) per ASTM B265 or ASTM F136.

  • ASTM B265 — Sheet, strip, and plate (both grades)
  • ASTM B348 — Bars and billets (both grades)
  • ASTM F136 — Grade 23 for surgical implants
  • ISO 5832-3 — Implants for surgery (Grade 23)