How to convert IGS to STL
- Add your .IGS file - drop it in the box above or click to browse.
- Convert it to .STL in a few seconds.
- Download your new .STL file.
What to expect
- IGES transfers geometry as individual NURBS surfaces that can have tiny gaps at edges - stitch surfaces in your CAD tool before exporting to avoid an open mesh that slicers reject.
- STL mesh resolution affects surface quality: lower the mesh deviation in FreeCAD or set refinement to High in Fusion 360 to reduce faceting on curved surfaces and fillets.
- STL carries no unit information - confirm the unit setting in your CAD tool matches the unit in your slicer, or the part will appear scaled by a factor of 25.4.
Frequently asked questions
The exported STL has holes - what do I do?
The source IGES model has surface gaps. Run the stitching command in your CAD tool - Part > Sew Shape in FreeCAD or Modify > Stitch in Fusion 360 - before exporting, and try increasing the stitch tolerance slightly.
What is the difference between .igs and .iges?
They are the same format -
.igs is the old three-character DOS spelling and .iges is the full extension; any CAD tool that reads one will read the other.Should I convert IGS to STL or to STEP first?
If you are going straight to a 3D printer, convert directly to STL. If you need to edit the geometry in another CAD program first, convert to STEP - it preserves solid structure better for further editing.
Can I convert a large or complex IGS assembly?
Yes, but complex assemblies may need manual inspection after conversion; check every body for gaps in your slicer before sending to the printer.
Programs that convert IGS: TurboCAD · ACE 3000 · CrossManager · MEDUSA4 · PolyTrans|CAD+DCC · SolidWorks · CATIA · 3ds Max (3D Studio Max)
