Same Ti-6Al-4V composition, but ELI (GR23) has tighter interstitial limits — oxygen ≤0.13%, iron ≤0.25%. The minimum tensile strength is lower (860 MPa vs 895 MPa for GR5) but ductility and fracture toughness are higher, which is why it is the medical implant and surgical instrument grade (ASTM F136).
TITANIUM · GR23
Ti-6Al-4V ELI (GR23) machined parts — ASTM F136 medical titanium
Ti-6Al-4V ELI is Ti-6Al-4V (GR5) with tighter limits on interstitial elements — oxygen, nitrogen, iron — for higher ductility and fracture toughness; it is the ASTM F136 grade (GR23) for medical implants and surgical instruments. Octud machines parts in this grade from customer drawings and delivers them in Korea with the mill test certificate.
The same Ti-6Al-4V as GR5, but a different standard. Parts entering the medical device value chain must call out ASTM F136 on the drawing and prove it with the mill certificate. This is the grade Octud supplies in production after sample validation.
ELI stands for Extra Low Interstitials. Limiting the oxygen, nitrogen, hydrogen, carbon and iron that sit between titanium atoms more tightly than GR5 trades a little strength for more ductility and fracture toughness — which is why it is used for implants under cyclic load, thin surgical instruments and housings that must not crack.
Machining behaves like GR5: hard, with low thermal conductivity that keeps cutting heat at the tool edge and wears tools fast. Medical parts add surface requirements — mirror polishing, specified roughness (Ra), edge radii. The housing Octud supplied combined a mirror-polished spherical exterior with an internal precision thread in one part.
What a buyer checks is the mill test certificate. In EN 10204 3.1 form it must carry heat number, chemical composition (Ti, Al, V, Fe, C, N, H, O) and tensile results so it can go into the device maker's regulatory file. Because the partner melts its own material, every lot traces back to the melt.
Specification requirements — ASTM F136 (annealed bar)
- Chemical composition
- Al 5.50–6.50 · V 3.50–4.50 · Fe ≤0.25 · O ≤0.13 · N ≤0.05 · C ≤0.08 · H ≤0.012 (wt.%)
- Tensile strength
- 860 MPa min.
- Yield strength
- 795 MPa min.
- Elongation · reduction of area
- 10% min. · 25% min.
- Density
- about 4.43 g/cm³
- Melting
- Double VAR (vacuum arc remelting) · titanium sponge feedstock
- Certificate
- EN 10204 3.1 — composition · tensile · ultrasonic · PMI · heat number
ASTM F136 · Octud delivered-lot certificate
Where it fits
- Orthopaedic and dental implant components
- Surgical instruments · handpieces
- Medical device housings · connectors
- Structural parts under cyclic load and fatigue
- Parts where GR5 lacked toughness
Before ordering
- 01Call out 'Ti-6Al-4V ELI, ASTM F136' on the drawing — 'Ti-6Al-4V' alone is quoted as industrial GR5
- 02Put surface requirements (Ra, polished area, edge radii) on the drawing
- 03Tell us at intake which documents your regulatory file needs beyond the MTC
- 042D (PDF) + 3D (STEP) together
Quotation and samples run through the Titanium parts page — the form is at the top of it.
Send a drawing for a quote