STEP Importer
.STEP Importer
A straightforward STEP import addon that allows you to directly select or drag-and-drop .step and .stp files into Blender without requiring external conversion tools or CAD software. Now includes post-import topology cleanup!
Features
- Topology Tesselation controls, with quality presets or fine grain control!
- Post-Import topology cleanup
- Basic material support, PBR coming when Cascadio supports it.
- Filter out non-solid STEP entities such as sketches and construction history.
- Drag and drop one or more STEP files directly into Blender.
Core Conversion Logic
This addon uses the Python library Cascadio to perform all STEP-to-mesh conversion. Cascadio converts STEP geometry into glTF data, which is then passed directly to Blender's built-in glTF importer. Mesh generation, object creation, and material assignment are therefore handled through Blender's existing glTF import pipeline.
FAQ
The geometry looks messy after import. Can this be improved?
It can! The import menu exposes a preset selection of quality presets, under "Topology Tessellation Quality". If you find your model has visible blockiness, try increasing the preset to a higher quality or choose "Custom" and enter your own values.
Additionally, if you choose "Clean Up Topology" when importing the add-on will perform a few safe operations to weld surfaces together and clean up overly tessellated faces.
Can I export STEP files as well?
No. STEP files store precise CAD geometry (B-Rep/NURBS surfaces), while Blender primarily works with polygon meshes. Once CAD data has been converted into triangles, the information required to recreate an accurate STEP model is no longer available. As a result, STEP export is outside the scope of this addon.
The exact naming structure from my CAD assembly doesn’t match what appears in Blender. Why?
Currently this is a limitation of cascadio, but it is one I already identified and patched. I am attempting get implemented. When the fix has been pushed upstream, I should be able to push out and update to fix it here. You can track that progress here
Non-standard characters import incorrectly. Do you plan to support them?
I've identified why these characters are corrupted, and I am working on getting the fix pushed upstream for OCCT itself. You can track that progress here
What's New
1.0.2 June 22nd, 2026
v.1.0.2 - Minor:
filepathno longer persists after first import, meaning you can "File > Import > STEP" as much as you need without needing to rely on drag and drop
I had to import a STEP-file on a PC where I didn't have my old add-on, so I decided to give a new one a try and this works flawlessly. Thank you for sharing!
Absolutely excellent. Imports are fast and smooth. This will speed up any workflow where CAD data is involved.
Thanks Works great in 5.1. Just a heads up 5.2 breaks it. Missing some of the import options. Also gets the error "Module 'cascadio' has no attribute load. " when trying to load a step file