A medical titanium bar enquiry fails in quieter ways than an industrial one. The quote comes back against the wrong specification, the certificate arrives without the interstitial results the auditor wants, or the heat traceability does not reach back to a single melt. This checklist walks through every line an implant-chain RFQ should carry, why each one exists, and the mistakes that cost buyers a requote or a rejected certificate. It is written for material sourcing of bar stock; device qualification and regulatory approval sit with the device maker and are out of scope here. For general industrial bar, use the Checkliste für Titanstab-Anfragen instead; this page covers what the medical chain adds on top.
Why a medical bar RFQ is different
Three things separate an implant-chain order from an industrial one. First, the material specification changes: the drawing cites ASTM F67, F136 or F1472 rather than the industrial B348, and an industrial certificate does not satisfy an implant line item even when the chemistry matches. Second, the evidence burden rises: the certificate must report the full interstitial analysis and tie every bar to its melt, because those records feed the device maker’s audit trail. Third, the documentation scope is itself a purchase requirement: quality-system scope, certificate format and inspection add-ons have to be named at RFQ stage, not discovered at receiving inspection.
The checklist at a glance
| # | RFQ line | What to state |
|---|---|---|
| 1 | Specification and grade | ASTM F67 (Grade 1 to 4), F136 or F1472, with the UNS number |
| 2 | Form and size | Diameter, length, cut tolerance |
| 3 | Condition and surface | Annealed; peeled, ground or polished; Ra when it matters |
| 4 | Chemistry reporting | Full interstitial analysis per heat: O, N, H, C, plus Fe |
| 5 | Mechanical testing | Tensile, yield, elongation; grain size where the drawing cites it |
| 6 | Microstructure | Acceptance per the cited specification |
| 7 | Rückverfolgbarkeit | Heat number, lot logic, EN 10204 3.1 |
| 8 | NDT and inspection | UT, dimensional, PMI or third-party witness as required |
| 9 | Quality system and documents | ISO 13485 scope statement, certificate format, language |
| 10 | Verpackung und Versand | Contamination control, marking, destination documents |
The sections below take the lines one at a time.
1. Specification and grade: name the implant standard, not the industrial one
The implant bar standards are ASTM F67 for unalloyed titanium in Grades 1 to 4, ASTM F136 for Ti-6Al-4V ELI (UNS R56401) and ASTM F1472 for standard-interstitial Ti-6Al-4V (UNS R56400). Write the specification and the UNS number on the same line, because the certificate must cite the standard the drawing calls for: Grade 23 bar certified to industrial B348 is chemically the same metal as F136 stock, but it is not a drop-in substitute on a body-contact part, and an auditor will read the certificate header before the chemistry table. The differences between the standards are set out in our F136 vs F67 quick reference und den F1472 and F620 guide.
2. Form and size: diameter, length and what the machinist needs
State the diameter with its tolerance, the length with its cut tolerance, and the quantity by weight or by piece count. For bar that will be Swiss-machined into screws or pins, the diameter tolerance and straightness drive the machine setup, so pull them from the process engineer rather than defaulting to the standard’s loosest class. If the bar is a forging input rather than a machining blank, say so: forging stock runs to different diameter logic, and the forging itself would run under ASTM F620, as covered in the implant forging guide.
3. Condition and surface finish
Implant bar is normally supplied annealed, with the surface peeled, ground or polished. Name the condition and the finish on separate lines. If the downstream process needs a maximum surface roughness, state the Ra value instead of the word polished, because polished is a workshop word and Ra is an acceptance number. Surface defects that survive to the finished implant are a rejection risk the device maker carries, which is why medical buyers tend to specify ground or better for close-tolerance bar.
4. Chemistry reporting: the interstitials are the point
For a high-value implant grade, the chemistry table on the certificate matters more than the nominal grade name. Ask for the full analysis per heat: oxygen, nitrogen, hydrogen and carbon, the interstitial elements, plus iron as a residual. Oxygen is the single most watched number, because it separates F136 ELI from standard Ti-6Al-4V: the ELI limit sits around 0.13% against about 0.20% for the standard grade, and that difference is what buys the higher fracture toughness and ductility the ELI grade is chosen for. A certificate that reports only the alloying elements and skips the interstitials is not enough for an implant-chain file. The metallurgy behind those limits, including how hydrogen is controlled at the mill, is covered in the Leitfaden zu Korngröße und Wasserstoffkontrolle.
5. Mechanical testing scope
Tensile strength, yield strength and elongation for the delivered heat are the baseline. Where the drawing cites a grain-size requirement, put it on the RFQ so the mill tests and reports it rather than treating it as a downstream problem. Reduction of area appears in the bar standards and is worth requesting for forging stock. State the test condition expected, normally annealed, so the reported numbers match the delivery condition.
6. Microstructure: the line most RFQs forget
The implant specifications carry microstructure acceptance requirements, not just chemistry and tensile numbers, and this is the line that separates a medical RFQ written by a buyer from one written with the metallurgist in the room. For Ti-6Al-4V ELI bar the concern is a fine, well-dispersed alpha-beta structure without the coarse or continuous alpha features that degrade fatigue performance. You do not need to write the metallurgy into the RFQ: it is enough to state that microstructure acceptance per the cited specification applies and that the mill confirms it in the documentation package. What matters is that the requirement is invoked before the order, because microstructure cannot be inspected into a bar after the fact.
7. Traceability: one heat, one paper trail when the file requires it
Implant-chain buyers often require each bar lot to trace to one melt, with the heat number marked on the material and repeated on every required document: certificate, packing list and shipping marks. If the project allows mixed-heat supply, write that explicitly; if it does not, state one heat per lot in the RFQ rather than assuming it will be inferred. When EN 10204 3.1 is specified, it is validated by the manufacturer’s authorised inspection representative independent of the manufacturing department and reports the agreed specific-inspection results. Define those results, material marking, lot or heat traceability, packing-document references and any one-heat-per-lot rule as one purchase requirement.
8. NDT and added inspection
Ultrasonic testing is the usual add-on for implant bar, and the RFQ should state the acceptance standard and coverage rather than the bare letters UT. Dimensional inspection reports, PMI checks and third-party witness inspection are all available levers; each adds cost and sometimes lead time, so name the ones the project file actually needs. A useful discipline: for every inspection line, write down who will read the resulting report. If no one will, the line is cost without a customer.
9. Quality system and the documents pack
State whether the order must be supplied under an ISO 13485 quality-system scope, and confirm that requirement at RFQ stage rather than at audit. Then define the documents pack in one block: certificate type and format, language, whether chemistry and mechanicals must appear on one certificate, and any customer-specific forms. Medical device makers often carry their own supplier questionnaires; sending them with the RFQ, rather than after the quote, is the single best way to keep the quoted price and lead time honest.
10. Packing, marking and contamination control
Titanium’s corrosion resistance does not remove the packing question: implant-chain buyers care about contamination control, separation from other alloys, and moisture. Specify separate packing by heat, marking that survives transit, and any cleanliness or wrapping requirement the receiving site imposes. Bars should arrive identifiable to their heat without opening every bundle.
Common mistakes that cost a requote
- Citing B348 when the file needs F136 or F67. The industrial standard is not an implant standard; the certificate header decides.
- Treating Grade 23 and F136 as the same callout. Grade 23 names the ELI alloy in the industrial system; F136 is the implant specification for it. The metal can be identical and the paperwork still wrong.
- Using the wrong UNS number for the chain. The medical chain keeps the material specification’s UNS, so F136 bar and its F620 forging stay R56401; the industrial forging chain under ASTM B381 assigns its own numbers, where the Grade F-23 forging is R56407. Match the number to the chain the drawing uses.
- Leaving surface as “polished” with no Ra, then rejecting bar that meets the specification but not the unstated expectation.
- Ordering without the interstitial reporting line, and discovering at audit that the certificate cannot demonstrate ELI limits.
- Adding every inspection option by default. Unread reports add cost and days without adding assurance.
Practical notes from the export desk
Two habits shorten the distance between enquiry and clean delivery. First, send the drawing note verbatim: the exact specification revision and any customer-spec overlay, rather than a paraphrase, because quoting against a paraphrase is how revision mismatches get built into an order. Second, ask the mill to confirm each RFQ line explicitly in the quotation, so the order documents inherit the full requirement set. Beiyu reviews each medical-chain line against mill capability before quoting, and where a customer specification adds tighter requirements, the order is made and certified to that specification. The wider picture of how implant-grade titanium is specified and bought is in the titanium for medical implants guide.
FAQ
What documents should come with medical titanium bar?
An EN 10204 3.1 mill test certificate reporting the delivered heat’s chemistry with full interstitial analysis and its mechanical results, tied to a heat number that is marked on the material and repeated on the packing documents. State at RFQ stage if the order must run under an ISO 13485 quality-system scope, and name any added inspection reports the project file requires.
Is ASTM B348 Grade 23 bar acceptable for an implant part?
Not as a substitute for an F136 line item. B348 is an industrial standard; F136 is the surgical-implant specification for the same ELI alloy, with implant-scope requirements an industrial certificate does not address. The certificate must cite the standard the drawing calls for.
Why do medical buyers ask for single-heat traceability?
Because the device maker’s audit trail runs from the finished implant back to the melt. Where the file requires one heat per lot, that requirement must be written into the RFQ and then repeated on the certificate, packing documents and material marking; otherwise the supplier may quote a compliant multi-heat lot against the standard but not against the project file.
What is the difference between F136 and F1472 for bar?
Both are surgical-implant specifications for wrought Ti-6Al-4V. F136 covers the ELI version, UNS R56401, with tighter interstitial limits and higher fracture toughness; F1472 covers the standard-interstitial version, UNS R56400. Which one applies is the device maker’s call; the mill certifies to the one on the order.
References
- ASTM F67, Standard Specification for Unalloyed Titanium for Surgical Implant Applications: astm.org/f0067
- ASTM F136, Standard Specification for Wrought Ti-6Al-4V ELI Alloy for Surgical Implant Applications: astm.org/f0136
- ASTM F1472, Standard Specification for Wrought Ti-6Al-4V Alloy for Surgical Implant Applications: astm.org/f1472
- EN 10204, Metallische Erzeugnisse, Arten von Prüfbescheinigungen
- ISO 13485, Medical devices, quality management systems: iso.org/standard/59752
Request a quote for medical-chain titanium bar
Send the specification and grade with the UNS number, diameter and length with tolerances, condition and surface with Ra where it matters, chemistry and mechanical reporting scope, traceability and certificate requirements, inspection add-ons, quality-system scope and destination. For commercially pure implant bar, review ASTM F67 titanium bar; for Ti-6Al-4V ELI, review Grade 23 ASTM F136 bar. Beiyu reviews each RFQ line against mill capability and confirms the available document scope before quotation. Kontaktieren Sie Beiyu Titanium für eine Anfrage.