Guides / Technical

How to write an RFQ package for machined medical components

September 27, 2026

A quote is only as accurate as the RFQ it is built from. The single biggest cause of a slow, wrong, or wildly inconsistent set of quotes is not a difficult part. It is an RFQ missing the information a supplier needs and is too polite, or too eager for the work, to ask for before quoting anyway.

The files, in order of what actually gets used

STEP file (AP214 or AP242). This is what a supplier programs from. Send the current revision, not an earlier one that happens to still be in your downloads folder.

PDF drawing with GD&T. Tolerances, datums, surface finish callouts and the material specification belong on the drawing, not in a cover email. A supplier quoting from the model alone has no way to know which faces actually matter.

Native CAD file, as backup. Useful when a supplier needs to check something the STEP translation lost, less often needed than people expect if the STEP and PDF are both current.

Sending a PDF drawing with no model is the single most common way to add a day to a quote. The supplier either reconstructs the geometry, which introduces the risk of a subtly wrong part, or comes back to ask for the model, which is the delay you were trying to avoid.

The callouts a drawing has to carry, not imply

Material and its standard, together. “Titanium” is not a specification. “Ti-6Al-4V ELI, ASTM F136” is. See titanium, 316L and PEEK for medical parts for how the standard changes both the price and the supplier pool.

Surface finish and post-processing. As-machined, passivated to ASTM A967, electropolished to ASTM B912, or anodized: state which one, because each is a different process step with its own cost and lead time, not a checkbox a supplier assumes for you.

Cleanliness or bioburden requirement, if one applies. A part destined for a cleanroom assembly has a different handling and packaging requirement than one that gets cleaned again downstream. Silence gets read as “not required,” which may not be your intent.

Marking requirement. UDI laser marking has to survive the finishing and sterilization steps that come after it, not just look good on the day it is cut. See UDI laser marking on machined implants for what to specify.

The information that lives outside the drawing

Quantity: this order and the realistic annual volume. A supplier pricing a part as a one-off will not invest in fixturing that would make a repeat lot cheaper. State both numbers even if the annual figure is a rough estimate.

Device classification, even roughly. Class I, II or III changes what evidence a supplier has to hold and produce, from a certificate of conformity up to full process validation and device history record entries. See the device classification breakdown for the requirement each class carries, or ask if you are not sure which class applies.

Quality requirement. ISO 13485 required, ISO 13485 preferred with ISO 9001 acceptable, or not yet decided. This one field changes which suppliers should even see the RFQ.

Target lead time and whether it is negotiable. “As soon as possible” quoted against every RFQ stops being useful information. A real date lets a supplier tell you honestly whether they can hit it, rather than promising and slipping.

Sterilization method, if the part is part of a sterile assembly. EO, gamma or e-beam can each impose different material and adhesive constraints. Deciding this after the machining supplier is already cutting parts is one of the more expensive sequencing mistakes in a device program. Detail in common mistakes when sourcing a machined medical part.

What NOT to include, and why it slows things down

Do not attach every revision of the drawing “for reference.” Send the current one, named clearly with its revision letter, and archive the rest. A supplier who is not sure which file is current will ask, or worse, will guess.

Do not describe the part’s function in place of specifying the tolerance. “This has to seal against the mating part” is useful context for a design conversation, not a substitute for the actual dimensional callout a machinist programs from.

Do not leave the material standard blank because “the supplier will know what we mean.” They will guess, and the guess is priced into the quote whether or not it is right.

A one-page RFQ checklist

1. STEP file, current revision
2. PDF drawing with GD&T, material and standard, surface finish
3. Quantity: this order and realistic annual volume
4. Tolerance on the tightest functional features
5. Device classification, at least roughly
6. Quality requirement: ISO 13485 required, preferred, or not decided
7. Cleanliness, marking and sterilization requirements, if applicable
8. Target lead time, stated as a real date

For how the quote that comes back is read and compared, see our guide to the medical machining quote.

An RFQ built to this checklist gets a faster, more accurate, and more comparable set of quotes than the same drawing sent with a cover email asking a supplier to “let us know your thoughts.” Send the drawing and it goes to machining suppliers that already run this material and this class of work.

Sources

• ASME Y14.5, Dimensioning and Tolerancing
• FDA, Design Controls guidance

Standards and regulations change. Check the current text at the source before you rely on it in a submission.

Frequently asked questions

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