A complete RFQ data package for a machined part has three parts: a PDF drawing that carries every requirement, a STEP model of the geometry, and a commercial sheet with quantities, delivery terms and certificate demands. Native CAD files are optional; they are needed only when the supplier has to edit the model, for example in redesign work.
What belongs in an RFQ data package?
A supplier prices what it can read. The drawing states the requirements: dimensions, tolerances, material, surface, treatment and notes. The 3D model states the geometry. The commercial sheet states what neither file shows: how many parts, delivered where and with which documents. The part number and revision on each file tie the three together.
When one part is missing, the supplier either asks or assumes. A question delays the quote. An assumption puts a risk margin into the quote, or a wrong price into the order. The technical drawing checklist covers what the drawing itself needs, including the title block data fields of ISO 7200.
Which file format does a supplier need, and when?
Send the PDF and the STEP file for every part. Add the other formats when the job needs them.
Table 1. File formats in an RFQ package
| Format | Carries | Send when |
|---|---|---|
| PDF drawing | All requirements: dimensions, tolerances, material, surface, notes | Always |
| STEP (ISO 10303-242) | Exact solid geometry and assembly structure; optionally tolerance annotations | Always for machined, welded and cast parts |
| DXF or DWG | 2D outlines and flat patterns | Sheet metal parts cut from a flat blank, in addition to the STEP model |
| Native CAD (SolidWorks, Creo, NX, CATIA, Inventor, Solid Edge) | Feature tree, parameters, native annotations | The supplier changes the design, or both sides agreed on model-based work |
| STL or other mesh | Triangle facets of a surface, no units | Scan data and additive parts; with reverse engineering jobs |
| BOM as spreadsheet | Item numbers, quantities, material, standard parts | Assemblies and welded assemblies |
Source: ISO 10303-242:2025 scope; Library of Congress description of the STL format; Autodesk DXF Reference.
DXF is not a neutral standard in the way STEP is: its specification, the DXF Reference, is published by Autodesk. It does the job it is used for, a 2D contour for a cutting machine, but it says nothing about material, thickness or bending, so the drawing still has to.
A mesh has no exact cylinders, planes or edges. A supplier cannot take a bore diameter from it the way it can from a STEP solid. STL files record no unit, so the reader has to assume the scale. The 3D scanning article explains when a mesh is the right starting point and how it becomes a model.
Which STEP version should you export?
STEP is the common name for ISO 10303, Industrial automation systems and integration: Product data representation and exchange. Two kinds of part matter in practice. ISO 10303-21:2016-03 defines the clear-text encoding of the file itself and replaced the 2002 edition. An application protocol (AP) defines what a file for a given purpose contains.
The mechanical protocols have been merged. ISO 10303-203:2011 was replaced by ISO 10303-242:2014, and ISO 10303-214:2010 was withdrawn on 2014-12-01 with the same successor. The current edition is ISO 10303-242:2025, published 2025-08-25, which replaced the 2022 edition. ISO lists it as to be revised, and a committee draft of the next edition exists. Status as of 2026-10-30.
Export AP242 where your CAD system offers it. Its scope includes dimensional and geometrical tolerance data and product documentation as annotated 3D models and as drawings.
That tolerance data can travel in the STEP file in two forms. The CAx Interoperability Forum recommended practices (version 4.1, 2024-06-20) separate semantic representation, which is machine-readable tolerance data, from graphic presentation, which draws the annotations as polylines or tessellated shapes. Whether the receiving software reads either form depends on that software. Treat the annotations in a STEP file as a convenience and put every requirement on the PDF drawing.
Export one STEP file per part number, name it with the part number and revision, and export solid bodies rather than loose surfaces. For an assembly, send the assembly structure as one STEP file and the individual parts as separate files.
Which document governs, the drawing or the model?
ISO 16792:2021, the standard for digital product definition data, supports two methods: a 3D model alone, or a 3D model together with a 2D drawing in digital form. Both are legitimate, so a package that contains both a model and a drawing has to say which one counts when they differ.
Write one sentence into the RFQ and the drawing notes: "The PDF drawing, revision C, governs. The STEP model is a geometry reference." For model-based work the sentence reads the other way and names the file, its revision and the software in which the annotations were created. For machined parts the drawing is the usual choice for the governing document, because a PDF displays the same on every machine.
ISO 16792:2021 is published, with a revision under development; DIN issued a German translation as DIN ISO 16792:2025-06.
What goes on the commercial sheet?
The commercial sheet is a short list in the body of the email or a one-page file. A quote depends on these entries:
- Quantity: the first order and the expected annual volume, as two separate figures. Set-up effort is spread over the batch, so the batch size changes the price per part.
- Delivery: the place, the Incoterms 2020 rule and the required date. The Incoterms article explains which rules fit shipments between Türkiye and the EU.
- Documents: the material certificate type, such as EN 10204 type 3.1, and any first article report, measurement report or certificate of conformity.
- Inspection: which features are measured, in what sample, and by whom.
- Surface treatment: coating or plating, and whether it comes before or after machining.
- Packaging and labelling: the label content and any packing specification.
- Alternatives: whether the supplier may propose another material or a relaxed tolerance, and whether a price for the alternative should be shown next to the base quote.
A supplier who may propose changes can point out a tolerance that adds machining time or a corner radius that no standard cutter produces. A supplier who is not asked quotes the drawing as it stands.
What does an incomplete package cost?
Each missing item has a specific consequence. No revision on the drawing means the quote refers to an unknown version. No general tolerance class means untoleranced dimensions have no agreed limit. A mesh in place of a solid means the supplier first rebuilds the geometry, and every rebuilt dimension is a place where the part can differ from your intent. A missing certificate requirement is discovered when the parts arrive without one.
None of these costs shows in the quote. They show up in lead time, in rework and in disputes at incoming inspection. When a drawing and a model disagree, the supplier made what one of the two files said, so the fix belongs in the package.
How do you send the package to us?
Our site has no upload form. Requests come by email, and a package for several parts fits one message.
Before sending, open the PDF and the STEP file once on a machine other than your own CAD workstation. A STEP file that shows the right geometry in a free viewer, and a PDF whose fonts and tolerance symbols display correctly, are the two files the supplier will work from.
Frequently asked questions
- Which files does a supplier need to quote a CNC part?
- A PDF drawing with all requirements, a STEP model of the geometry, and the commercial data: quantity, delivery terms and required certificates. Native CAD, STL and DXF are needed only for specific jobs.
- Is a STEP file enough without a drawing?
- Only if the contract makes the annotated 3D model the governing document. ISO 16792:2021 supports a 3D model alone or a 3D model with a 2D drawing, so the RFQ has to say which applies. Without that statement, send a PDF drawing as well.
- Do I have to send native CAD files?
- No, not for a quote on a machined part. A STEP file carries the geometry in a neutral format. Send native CAD when the supplier is asked to change the design or when both sides have agreed on a model-based workflow.
- Which STEP version should I export, AP203, AP214 or AP242?
- AP242 where your CAD system offers it. ISO 10303-203 and ISO 10303-214 were replaced by ISO 10303-242 in 2014, and the current edition is ISO 10303-242:2025.
- Can I send an STL file instead of STEP?
- Not for a machined part. An STL file holds triangle facets only and no units, so it has no exact bores, planes or edges. Use it for scan data or additive parts, and send STEP for anything machined.
Sources
- ISO 10303-242:2025, Managed model-based 3D engineering (Genorma catalogue record: published 2025-08-25, stage 90.92)
- ISO 10303-242:2022, withdrawn 2025-08-25, revised by ISO 10303-242:2025 (Genorma)
- ISO 10303-203:2011, withdrawn, replaced by ISO 10303-242:2014-12 (DIN Media)
- ISO 10303-214:2010, withdrawn 2014-12-01, revised by ISO 10303-242:2014 (ISS, national ISO member)
- ISO 10303-21:2016-03, Clear text encoding of the exchange structure, current (DIN Media)
- ISO 16792:2021, Digital product definition data practices (Genorma: published 2021-04-07, stage 90.92, revision in development)
- DIN ISO 16792:2025-06, German translation of ISO 16792:2021 (DIN Media)
- CAx-IF Recommended Practices for the Representation and Presentation of PMI (AP242), version 4.1, 2024-06-20
- STL (STereoLithography) File Format Family (US Library of Congress)
- AutoCAD DXF Archive: the DXF Reference is published by Autodesk (Autodesk Platform Services)
- ISO 7200:2004, Data fields in title blocks and document headers (ISS: confirmed 2025-01-08)
Questions on a drawing? sales@ertas.engineering