PTC
Exporting STEP from Onshape and checking your BOM.
Onshape exports from the tab of your assembly. With the BOM, watch out for one thing: without expanded subassemblies you do not export everything.
Published 20 September 2026
01 Export
Exporting STEP from Onshape.
- 1 Right-click the assembly tab and choose Export.
- 2 Choose STEP as format and AP214 or AP242 as version.
- 3 Export to your computer and check the file in the free STEP viewer.
One file or loose parts
In the export, choose that the assembly goes out as one file. Loose files per part are harder to check and to share.
02 BOM
BOM from Onshape to Excel.
- 1 Open the BOM table of your assembly and set the view to Structured.
- 2 Click the menu with the three dots at the top right of the table and choose Expand All: without expanded subassemblies you do not export the whole list.
- 3 Then choose Export to CSV and open the file in Excel.
No BOM at hand? The free STEP to Excel makes one from the model itself: per part the total quantity, the material and the dimensions.
03 Check
Does the model match the BOM?
Export the STEP and the BOM at the same moment: otherwise you compare two versions. Then you can lay them against each other.
Free, in your browser
- Parts or subassemblies lying double in the same place
- Parts that touch nothing, with the distance in mm
- Parts without material or with a default value such as Generic
- The same shape under different names
With BOMproof
Your drawing and your BOM as well.
BOMproof lays the STEP from Onshape next to your PDF drawings and your Excel BOM: quantities per position, title block and revisions, materials on the drawing against the model. Every comment gets a pin in 3D and a balloon on the drawing.
Sources
04 Frequently asked questions
Onshape and STEP.
01 Why is half of my BOM missing after the export?
Probably the subassemblies were collapsed. Set the BOM to Structured, choose Expand All in the table menu and only then export to CSV.
02 Which STEP version is best to export from Onshape?
AP214 or AP242. Both contain the product structure with assemblies, parts and quantities, which is what you need for a BOM and a check on the model. AP203 works too, but contains less (for example no colours).
03 Can I view such an export without a CAD licence?
Yes. Open the .stp or .step file in the free STEP viewer on this site: you see the 3D model, the product structure and the BOM, and you can download the BOM as Excel. The file stays on your own computer.
05 Other packages
Working with something else?
From export to demonstrably good release.
Export your STEP from Onshape, upload the drawings and the BOM with it and let BOMproof check them against each other. Book a demo with your own design.