STEP · 3MF
STEP vs 3MF
STEP is the CAD source; 3MF is the print package. One keeps exact surfaces and features, the other keeps a mesh with a declared unit, colours and object structure.
| Criterion | STEP | 3MF |
|---|---|---|
| What it stores | B-Rep surfaces and solids | Mesh, units, materials and objects |
| Precision | Exact curves and surfaces | Faceted approximation |
| Units | Declared in the file | Declared, usually millimetres |
| 3D printing | Must be tessellated first | Slicers read it directly |
| Colours and objects | Limited: names and face colours | Base colours, materials and named objects |
| Editing | Parametric CAD tools | Mesh editors and slicers |
In short. Keep STEP as the source and export 3MF for the slicer when it supports it. STL remains the universal fallback; neither print format restores the CAD features.
Convert between them
Format pages
Questions
Is 3MF better than STEP for printing?+
Yes for slicers: 3MF is a mesh with units and materials. A STEP file must be tessellated first.
Does 3MF keep exact dimensions?+
Overall dimensions and placement are kept, but curved surfaces become triangles.
Can I go back from 3MF to STEP?+
No. You can wrap a mesh in STEP, but the exact surfaces, features and constraints are lost.