STEP to STL Converter

STEP to STL Converter

Convert parametric CAD STEP files from SolidWorks, CATIA, Fusion 360, and FreeCAD to STL for 3D printing. Fine-tune chord height and angular deflection for optimal print quality. No software installation required.

Drag & drop your STEP file here

or click to browse (Max 50MB for free users)

Supported: .step, .stp files

Why Convert STEP to STL?

STEP stores engineering precision. STL stores printable triangles. Convert parametric CAD solids into files your 3D printer can slice.

CAD to 3D Print

Transform parametric STEP solids from SolidWorks, CATIA, Fusion 360, or FreeCAD into STL files ready for FDM, SLA, and SLS 3D printing with any slicer.

Precision Control

Fine-tune chord height (0.001mm for engineering parts) and angular deflection to balance surface quality with polygon count and file size.

Watertight Meshes

OpenCASCADE tessellation produces manifold, watertight STL with correct face normals. No holes, no flipped faces, print-ready output every time.

Multi-CAD Support

Import STEP from SolidWorks, CATIA, Fusion 360, Siemens NX, FreeCAD, Onshape, Inventor, Creo, and any STEP-compatible CAD system.

About STEP to STL Conversion

Why convert STEP to STL?

STEP (STandard for the Exchange of Product data, ISO 10303) is the modern neutral CAD format, it stores parametric solids, NURBS surfaces, and assembly structures with mathematical precision. STL (Stereolithography) is the universal 3D printing format. A simple triangle mesh that every slicer can process. Converting STEP to STL tessellates CAD precision into printable triangles: your engineering model becomes a physical object.

What is preserved during conversion?

Geometric accuracy is controlled by chord height (maximum distance between NURBS surface and mesh face) and angular deflection (maximum angle between adjacent faces). Tighter tolerances produce more polygons but better surface reproduction. The resulting STL is a watertight triangle mesh with correct face normals. STEP colors, materials, assembly structure, and metadata are not preserved. STL is a geometry-only format storing only triangle coordinates and face normals.

How to use the converted STL file

The STL file imports directly into Cura, PrusaSlicer, Bambu Studio, Simplify3D, Lychee Slicer, Chitubox, or any 3D printing slicer. Scale your model in the slicer to match desired print dimensions, select your material (PLA, ABS, PETG, resin), configure layer height and infill, slice, and print. For assemblies, convert each STEP part individually for best results.

How to Convert STEP to STL

Three steps to convert your parametric CAD STEP solids into 3D-printable STL files.

1

Upload Your STEP File

Drag and drop your .step or .stp file from SolidWorks, CATIA, Fusion 360, FreeCAD, or any CAD system. Free tier: up to 50MB per file.

2

Tessellate to STL

Our cloud engine uses OpenCASCADE to tessellate STEP NURBS surfaces into watertight triangle meshes. Adjust chord height and angular deflection for optimal print quality.

3

Slice & Print

Download your STL and import into Cura, PrusaSlicer, or Bambu Studio. Scale, slice, and print. Files auto-delete within 1 hour.

Related Converters

Converting CAD STEP to 3D printing? These converters complete your engineering pipeline.

STEP to OBJ
Convert parametric STEP CAD solids to editable OBJ polygon meshes.
IGES to STL
Convert legacy IGES CAD files to STL for 3D printing.
OBJ to STL
Convert OBJ meshes to STL for Cura, PrusaSlicer, or Bambu Studio.
STL to OBJ
Convert 3D printing STL files to editable OBJ meshes.
FBX to STL
Convert game-ready FBX models to STL for 3D printing.
FAQ

Frequently Asked Questions

Upload your .step or .stp file and click Convert to STL. Our engine uses OpenCASCADE to tessellate the NURBS surfaces into a watertight triangle mesh with configurable chord height and angular deflection. The STL is ready for slicing in Cura, PrusaSlicer, Bambu Studio, or any 3D printing slicer. For engineering parts, use chord height 0.001mm and angular deflection 0.5° for optimal surface quality.
Yes. You can convert up to 3 files per day for free with files up to 50MB each. For unlimited conversions, 500MB files, and batch processing, upgrade to Pro.
For high-precision engineering parts: chord height 0.001mm, angular deflection 0.5°. For general prototyping: chord height 0.01mm, angular deflection 1°. For quick visual prototypes: chord height 0.1mm, angular deflection 5°. Tighter tolerances = more triangles = larger files but better surface quality for organic shapes and precision fits.
Yes. Our OpenCASCADE tessellation engine produces manifold, watertight meshes. However, STEP files with modeling errors or non-manifold geometry may produce imperfect results. Always inspect the STL in your slicer's preview before printing. Use our Mesh Repair tool for any issues.
STEP exports are available from SolidWorks, CATIA, Fusion 360, Siemens NX, FreeCAD, Onshape, Autodesk Inventor, PTC Creo, Solid Edge, Rhino, and virtually every modern CAD system. STEP (ISO 10303) is the universal neutral format for engineering data exchange.
Absolutely. All uploads use TLS 1.3 encryption. Files are processed in isolated cloud environments and auto-deleted within 1 hour. Read our Privacy Policy for full details.
Free users: 50MB. Basic: 100MB. Pro: 500MB. Team): 1GB. Complex assemblies produce large STEP files convert individual parts for better results on the free tier.