CAD Preparation for Quoting
Exporting STEP correctly: units, scale, solid bodies, coordinate system and file size
A quote is only as good as the file it reads. Preparing CAD for quoting means: export STEP AP214 from native CAD, verify units and scale (mm vs inch), ensure a single solid body (watertight), set the coordinate system to the datum scheme, strip reference geometry, and keep the file under ~200 MB. These five steps eliminate the most common quoting errors — wrong size, missing bodies and misread datums.
1. Export the right format
STEP AP214 is the universal quoting format: exact B-rep geometry, no mesh loss, color/layer metadata optional. Export from the native CAD (File → Save As → STEP) at the same units as the model; keep AP203 for simple geometry-only parts.
Avoid screenshots, PDFs and drawings-only uploads for quoting — the engine needs 3D geometry. For 2D laser/sheet parts, DXF with a thickness note is accepted.
2. Units, scale and size
State units on the drawing and in the file: a 25.4 mm part interpreted as inches quotes 25× wrong. Most CAD exports embed units; the platform detects them and shows the resulting L/W/H for confirmation.
Check scale after export (measure a known feature), keep files under ~200 MB, and split very large assemblies into individual part files. Avoid STL for machined parts — the facets approximate radii and the engine over-reads volume.
3. Model hygiene
Quote the manufacturing body: suppress reference bodies, sketches, construction geometry and mates before export. Ensure the body is a single solid (no open shells — scan/mesh files often leak) and that surfaces are clean (no self-intersections).
Set the part origin/coordinate system to the datum scheme you want measured; the engine reads the bounding box from the model orientation. For thin parts, confirm the thickness direction is correct in the L/W/H shown.
4. Attaching requirements
Attach the drawing/PDF alongside the 3D file when the part has PMI, threads, finish or GD&T notes that are not in the model; reference the drawing revision on the PO so factory and inspection match.
For assemblies, upload parts individually or a zipped folder; state quantity per line item. The quoting engine then prices each part and the batch rolls up into one order.
Quick reference
| Check | Action |
|---|---|
| Format | Export STEP AP214 (not STL for machined) |
| Units | Confirm mm/inch; measure a known feature |
| Scale | Verify after export |
| Solid body | One watertight solid per file |
| Reference geometry | Suppress sketches/mates/bodies |
| Coordinate system | Align to datum scheme |
| File size | < 200 MB; split assemblies |
| Drawing | Attach PDF with notes/rev when needed |
Sources & references
- ISO 10303 — STEP
- Xometry Learning Center — CAD Preparation (public engineering reference)