Grade 23 and Grade 5 are both Ti-6Al-4V titanium routes. Grade 23 is the extra-low-interstitial (ELI) variant; it is not commercially pure titanium. The purchasing decision starts with the governing material specification, not with an assumption that the higher grade number means a universally better powder.
Grade 23 or Grade 5: the short answer
If the drawing or approved manufacturing route calls for Ti-6Al-4V ELI, evaluate Ti64 Grade 23 powder. If it calls for Grade 5 Ti-6Al-4V, evaluate Grade 5 powder. When the grade is unresolved, ask the design and process owners to agree the chemistry and final-part requirements before comparing quotations.
| Purchasing question | Grade 5 Ti-6Al-4V | Grade 23 Ti-6Al-4V ELI |
|---|---|---|
| Grade requirement | Confirm the standard Ti-6Al-4V specification and edition | Confirm the ELI specification and edition explicitly |
| Chemistry review | Match every required element to the agreed limits | Check the ELI limits, including the specified interstitial controls; a generic Ti64 COA is insufficient |
| PBF component framework | ASTM F2924 where specified by the purchaser | ASTM F3001 where specified by the purchaser |
| Powder evidence | Lot COA, measured PSD, morphology, condition and traceability | The same evidence, evaluated against the ELI purchase requirements |
| Part evidence | Properties for the actual build and post-processing condition | Properties for the actual ELI build and post-processing condition |
| Substitution | Do not replace with Grade 23 without approval | Do not accept Grade 5 because the nominal alloy family matches |
What ELI changes, and what it does not prove
ELI identifies a tighter interstitial-control basis. It does not give a universal oxygen limit for every titanium purchase. State the governing specification, edition, required elements, limits and test methods; compare the actual lot results against those requirements. Use the titanium oxygen-limit guide to separate a powder acceptance limit from a finished-part requirement.
Do not infer toughness, ductility, fatigue life or a guaranteed strength difference from the powder label alone. Ask for evidence tied to the machine, parameter set, orientation, thermal treatment and final surface condition being proposed. Results from another condition are not an acceptance certificate for this build.
Use the right standard at the right level
ASTM F2924-14(2021) addresses Ti-6Al-4V components produced by powder bed fusion. ASTM F3001-14(2021) addresses the ELI component route. These are component specifications, not proof that any powder carrying a Grade 5 or Grade 23 label qualifies the complete manufacturing route.
Agree the powder purchasing specification separately, including chemistry, PSD measurement, sampling, morphology, contamination controls and lot traceability. Carry any purchaser-specific requirements into the order; do not rely on a general brochure or an unqualified claim of compliance.
Questions to resolve before changing Ti64 grades
- Does the approved drawing permit the proposed grade and specification?
- Is the machine and parameter route established for that powder and its measured PSD?
- Are powder history, reuse controls, packaging and change notification documented?
- Which build coupons, post-processing records and final inspections are required?
- Would a grade change require a new qualification or customer approval?
A label such as “medical grade” does not establish device acceptance. For an implant program, continue with the Grade 23 medical application guide. For guide or instrument hardware, use the surgical guide and instrument requirements. Those applications have different acceptance questions.
If the choice is actually Ti64 versus commercially pure titanium, use the separate Ti64 vs Grade 2 comparison.
Send a grade-specific powder RFQ
Include Grade 5 or Grade 23, specification and edition, process and machine, target PSD, chemistry requirements, virgin or reused condition, quantity, destination and qualification stage. Request the lot COA, PSD report, TDS/SDS, available SEM or morphology evidence and packaging details.
Request Grade 5 powder or request Grade 23 ELI powder. The selected grade is carried into the RFQ so technical review starts with the intended material.