Convert STEP to STL
Online
Turn CAD geometry into a 3D-printable mesh. Bring your SolidWorks, Fusion 360, or FreeCAD designs directly to the printer.
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What Happens During Conversion
Parse STEP Geometry
FreeCAD's OpenCASCADE kernel reads the STEP file and reconstructs the B-rep solid — planes, cylinders, NURBS surfaces — into a precise mathematical model in memory.
Tessellate Surfaces
Each mathematical surface is approximated by a set of triangles. The deflection parameter controls how closely the triangles follow the original curves — lower means finer, more accurate mesh.
Export STL
The triangle mesh is written as a binary STL file, ready to open in any slicer. Normals are computed automatically so slicers read the inside/outside correctly.
Mesh Quality Guide
| Deflection | Quality | File Size | Best For |
|---|---|---|---|
| 0.01 | Very fine | Large | Precision parts, fine curved surfaces |
| 0.05 | Fine | Medium | Most functional 3D printing |
| 0.1 | Standard | Small | Quick prints, blocky geometry |
| 0.5 | Coarse | Very small | Visualization, low-poly preview |
Default deflection is 0.1. Lower values produce more triangles and larger files but better represent curved surfaces.