CAD → mesh
Upload a STEP (.step / .stp) file and download a tessellated STL mesh.
Everything runs in your browser — your files are never uploaded. STEP/IGES use the OpenCASCADE engine (a one-time ~7 MB download) and are tessellated into a mesh, so the result is a surface model, not editable CAD history.
STEP to STL conversion is the process of translating parametric CAD geometry (stored in STEP format) into a triangle mesh representation (STL format). STEP files preserve solid geometry and tolerances, while STL represents shapes as linked triangles, which is the universal format for 3D printing and mesh software.
The converter reads your STEP file, tessellates the solid geometry into a triangle mesh at a specified resolution, and exports the mesh as binary or ASCII STL. Higher tessellation density produces smoother surfaces but larger file sizes; lower density runs faster but may show faceting on curved surfaces.
| Input | Result | Notes |
|---|---|---|
| Mechanical part STEP file (gear.step), 50 kB, with curved surfaces | Binary STL mesh, 2.1 MB, 125,000 triangles, smooth surface reproduction | Default tessellation captures surface detail suitable for 3D printing |
| Automotive bracket STEP (tolerance ±0.05 mm), complex edges | STL file, 5.8 MB, 320,000 triangles, fine edge definition | Tighter mesh setting preserves sharp features and press-fit geometry |
| Architectural column STEP, large simple geometry, 200 kB | STL, 800 kB, 45,000 triangles, coarse mesh | Loose tessellation acceptable for visualization; much faster, smaller export |
STEP stores 3D geometry as mathematical solids with edges, faces, and parameters; STL represents shapes as a collection of triangles. STEP is editable in CAD; STL is a fixed mesh used for printing and rendering.
No. STL is a mesh approximation. Fine details and tight tolerances from STEP may be lost, especially if tessellation is coarse. Always verify scale and fit after conversion.
Most online converters handle STEP files up to 100–200 MB. Very large assemblies may time out; consider simplifying geometry or converting parts separately.
Yes, using desktop CAD software (SolidWorks, FreeCAD, Fusion 360) or open-source libraries like Open Cascade. This tool offers online convenience without installation.
Binary STL is smaller and faster to process; most 3D printers prefer it. ASCII is human-readable but 4–5 times larger. Choose binary for printing, ASCII for inspection or custom processing.
Coarse tessellation creates visible triangles, especially on curves. Increase mesh density or check that the original STEP geometry was solid and watertight.