High-Quality STEP to STL — Smooth, Not Faceted
Control the mesh resolution so curved surfaces stay smooth.
STEP and IGES are exact math surfaces; STL is triangles. The conversion deflection decides whether your curves look smooth or chunky. 3D CAD Converter gives you full control.
Download Free TrialFree trial: 10 conversions with every feature. No credit card required. Windows 10/11.
Draft, Standard, Fine or Ultra-Fine — set linear and angular deflection precisely, per batch.
Faceted curves ruin the result
Without 3D CAD Converter
- Default exporters chop circles into coarse facets you can see and feel.
- No way to dial in mesh resolution per job.
- Either huge files or visibly low-poly surfaces — never the right balance.
- Re-exporting one file at a time from heavy CAD software.
With 3D CAD Converter
- Set linear + angular deflection to make curves as smooth as you need.
- Four presets from Draft to Ultra-Fine, or type exact values.
- Tune file size vs. smoothness for printing, rendering, or the web.
- Batch a whole folder at one quality level in a single click.
Tessellation control that matters
The two values OpenCASCADE uses to mesh B-Rep surfaces. Lower = smoother curves and more triangles.
Draft, Standard, Fine, and Ultra-Fine cover most jobs; override the exact numbers any time.
Apply the same deflection to hundreds of STEP/IGES files and convert the whole folder offline.
Pass --tessellation and --angular on the command line to automate high-quality conversions.
Tessellation presets
| Preset | Linear deflection | Angular deflection (radians) | Best for |
|---|---|---|---|
| Draft | 1.0 | 5.0 | Fast previews, rough mockups |
| Standard | 0.1 | 0.5 (≈29°) | Everyday 3D printing and viewing |
| Fine | 0.01 | 0.1 (≈6°) | Smooth prints, close-up renders |
| Ultra-Fine | 0.001 | 0.05 (≈3°) | Polished curves, presentation models |
Watch a STEP file become a print-ready STL
Command-line examples
# Fine mesh from a single STEP file cadconvert convert -i bracket.step -o bracket.stl --tessellation 0.01 --angular 0.1 # Ultra-fine batch of a whole folder to STL cadconvert batch -i .\parts -o .\out -f stl --tessellation 0.001 --angular 0.05
How It Works
Download & Install
Free trial: 10 conversions with every feature. Windows 10/11.
Pick a quality preset
Choose Draft to Ultra-Fine, or type exact linear and angular deflection values.
Click Convert
Batch processing handles entire folders with progress tracking and ETA.
Stop Paying Annual Subscriptions
| Tool | Price | Model |
|---|---|---|
| CAD Exchanger | Subscription (annual renewal) | |
| Spin 3D | Subscription (annual renewal) | |
| 3D CAD Converter | $179 | ✔ Pay once, own forever |
Free trial: 10 conversions with every feature. No credit card required. Windows 10/11.