STEP export for SketchUp · ISO 10303-21 AP214
“Can you send me a STEP?” Yes.
The button SketchUp never had. Curves intact, units in millimetres.
No credit card. The check runs on your own model.
Sound familiar?
The moment a client asks for a STEP, you find out SketchUp cannot.
SketchUp exports DWG and DXF, not STEP. The workarounds hand over a dumb solid made of flat facets. So you redraw, you outsource, or you say no.
SketchUp’s own CAD export list: DWG and DXF, no STEP.
Trimble CAD export documentation, checked 24 July 2026
Why this gives you real curves
The round information is already in your model.
SketchUp already knows
For every arc, SketchUp stores the exact centre, radius and normal. Those numbers are sitting in your model.
We read them back
Round mode reads that data and rebuilds true surfaces: a hole becomes a cylinder, a tapered hole a cone, a ball a sphere.
Nothing guessed from triangles
Was the curve data destroyed? A geometric re-fit rebuilds it from the vertices, with a guard so a deliberate hexagon stays a hexagon.
What ends up in the STEP
Round where you drew round. Honest where it is not.
Comes back
- Drilled holes and tubes come back round and watertight
- Bends and fillets as cylindrical or conical faces
- One named solid per object in an AP214 assembly
- Tags per solid, units in millimetres
- Unreadable geometry falls back to flat. It never crashes.
Stays flat, on purpose
- Triangulated walls (strips are chained as quads)
- Non-uniform scale: an ellipse is exported flat
- Coarse tessellation: under 12 segments per circle
- Partial spheres: detection works on whole objects
Not CAM, not AP242 or PMI, not a feature tree. It writes geometry.
From the people who tested it
Also in Transl8: 2D export to DWG and DXF. STEP and IGES import planned.
Questions
What people ask before they try it.
Which file do I send back?
An ISO 10303-21 AP214 STEP file. A watertight object becomes a closed solid, an open one a surface model, and units are millimetres.
Is this a real STEP file, or a mesh with a .step extension?
A real one: ISO 10303-21, AP214, B-rep. A watertight object becomes a closed solid, an open one a surface model. Segmented mode writes flat faces, which is still a valid solid. Round mode brings the curved geometry back as curved surfaces.
My model came from an import and the curves are gone.
A second pass measures the vertices. SketchUp tessellates arcs at equal steps, so equal chords turning by equal angles are fitted to a circle and checked point by point before they are accepted. A guard keeps a deliberate hexagon a hexagon.
How much of my model actually comes back round?
Your modelling habits decide that. That is why the analysis comes first and is free: you see per object what comes back round and what stays flat, before you decide anything.
Free roundness analysis
Send one part and see what comes back
- Tell us who receives your STEP.
- Send one representative model.
- Get the report: what comes back round, and what stays flat.
Reply within one working day. If this would not help you, we will say that too.