Titanium Alloy Grades Complete Guide: Grade 1-4 vs Ti-6Al-4V vs ELI

Titanium isn't just "Grade 5" — performance varies widely across grades.

Pure Titanium (Grade 1-4)

• Grade 1: Softest, most corrosion-resistant. ~240 MPa tensile. Chemical reactor liners, seawater piping.
• Grade 2: General-purpose CP titanium. ~345 MPa. Medical, chemical, marine.
• Grade 3-4: Higher strength CP. Grade 4 reaches ~550 MPa. Aerospace fasteners.

Ti-6Al-4V (Grade 5) — the workhorse

The standard. 950-1100 MPa tensile, 56% the density of steel. ~50%+ of all titanium consumption. Aerospace structures, satellites, high-end exhaust, premium bicycles.

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

Extra Low Interstitial — lower oxygen, nitrogen, carbon, iron. Better toughness and fatigue. Reserved for medical implants. ~30-50% more expensive than standard Grade 5.

Other grades (briefly)

• Grade 7 (Pd-Ti): extreme corrosion resistance, costly
• Grade 9 (3-2.5): mid-strength, sports equipment
• Grade 12: corrosion-resistant heat exchangers
• Grade 19 (Beta-C): heat-treatable beta alloy

Selection guide

1. Body implant? → Grade 23 (ELI)
2. Extreme corrosion? → Grade 1-2 or Grade 7
3. Strength priority? → Grade 5
4. Default fallback? → Grade 5 covers 90% of applications

Machining notes

All titanium grades demand low thermal conductivity, work-hardening tendency, and reactivity at elevated temperatures. Coated carbide or ceramic inserts required. Difficulty: pure Ti < Grade 4 < Ti-6Al-4V < beta alloys.