The drawing decides, not the price
ASTM F67 and ASTM F136 are both surgical implant material standards, but they cover different metals. F67 covers unalloyed titanium. F136 covers the Ti-6Al-4V ELI alloy. Substituting one for the other is a material change, not a sourcing preference, and it is decided by the approved design rather than at the purchase order stage.
| Standard | Material it covers |
|---|---|
| ASTM F67 | Unalloyed titanium for surgical implant applications |
| ASTM F136 | Wrought Ti-6Al-4V ELI alloy for surgical implant applications |
What changes mechanically when you move between them
Minimum mechanical values come from the implant standard the order runs under, not from the industrial product standard for the same grade. The two are not the same numbers, which is why the specification chain has to be named before anything is quoted.
| Ordered standard | Minimum mechanical values |
|---|---|
| ASTM F136 (Ti-6Al-4V ELI) | 860 MPa tensile, 795 MPa yield, 10% elongation, 25% reduction of area |
| ASTM F67 (unalloyed) | Per the grade table of ASTM F67 for the ordered grade |
| ASTM B348 or B265 (same alloys, industrial route) | Per that standard’s own table, which is not interchangeable with the implant figures |
The UNS number is not a single value for Grade 23
This is the field that most often turns into a rejected certificate. The same alloy carries a different UNS number depending on which specification the order was placed against.
| Ordered standard | UNS for the Ti-6Al-4V ELI grade |
|---|---|
| ASTM F136 (surgical implant) | R56401 |
| ASTM B348 (bar and billet) | R56407 |
| ASTM B265 (strip, sheet and plate) | R56407 |
| ASTM B381 (forgings) | R56407 |
Match the UNS on the certificate to the specification chain named on the drawing. A certificate showing the industrial UNS against an implant specification, or the reverse, is the common cause of a document rejection late in the project.
What ELI actually restricts
ELI means extra low interstitial. The alloy chemistry limits the interstitial elements more tightly than the general-purpose version of the same alloy.
| Grade | Selected composition limits, mass percent |
|---|---|
| Grade 23 Ti-6Al-4V ELI | Ti-6Al-4V ELI (Al 5.5 to 6.5, V 3.5 to 4.5, O 0.13 max) |
| Grade 2 unalloyed | Unalloyed Ti, O 0.25 max, Fe 0.30 max |
| Grade 4 unalloyed | Unalloyed Ti, O 0.40 max, Fe 0.50 max |
Full chemistry is per the governing specification. The limits above are the fields most often checked on an incoming certificate.
European drawings may not name an ASTM standard at all
Buyers working to European documentation may cite ISO 5832-3 in place of an ASTM implant specification. Where a drawing names an ISO specification, the requirements have to be reconciled against the ordered standard rather than assumed equivalent.
What the order line has to carry either way
| Field | Why it is on the line |
|---|---|
| Implant standard | Names the specification chain the certificate must match |
| Grade | Names the material inside that standard |
| UNS | Must be the number that belongs to the named standard |
| Condition and surface | Drives the tolerance and the machining allowance |
| Inspection and certificate scope | Decides what the mill has to report and when |
Lines to paste into your purchase order
Implant standard: ______ (ASTM F67 or ASTM F136, or the ISO specification named on the drawing) Grade: ______ UNS: ______ (must match the standard named above) Form and dimensions: ______ Condition: ______ Surface: ______ (state a roughness value where it is an acceptance criterion) Inspection scope: ______ (examination, acceptance standard, class and stage) Certificate: EN 10204 3.1 inspection certificate, chemistry traceable to heat number, mechanical results and inspection lot identification per the governing specification
Send the drawing with the specification chain named and Beiyu confirms the grade, UNS and certificate scope against that chain before pricing.
Specification detail with sources
The industrial and implant specification chains carry different UNS numbers for the same alloy, which is the single field that most often causes a certificate to be rejected. Grade 23 ELI ordered to ASTM B348, B265, B381 or B863 is UNS R56407; ordered to ASTM F136 for surgical implants it is UNS R56401. Take the number from the specification named on the drawing rather than from a general grade table.
| Specification the order runs under | UNS for Ti-6Al-4V ELI |
|---|---|
| ASTM B348, B265, B381, B863 | R56407 |
| ASTM F136, surgical implants | R56401 |
Where the industrial chain applies, its interstitial limits are stated in the product standard: ASTM B348 sets Grade 23 ELI at 0.13 percent oxygen maximum, 0.03 percent nitrogen maximum, 0.08 percent carbon maximum and 0.0125 percent hydrogen maximum, against 0.20 percent oxygen maximum for standard Grade 5 (ASTM B348, chemical requirements). ASTM B348 also requires hydrogen to be reported on the finished product, while ingot hydrogen need not be (ASTM B348, chemical requirements, table notes). Naming the UNS settles which specification the certificate is written against. It does not by itself establish that the mechanical minima reported on that certificate come from the implant standard rather than the industrial one. Those figures belong to the industrial chain. Minimum mechanical values for an implant order come from the implant specification named on the drawing, not from the industrial product standard, so the specification chain has to be named before anything is quoted.
Send a technical RFQ
For implant grade titanium bar RFQs, include the drawing, the full specification chain, grade and UNS as named in that chain, diameter, condition, surface finish, tolerance, examination scope and the required certificate package.