Exporting to STEP format (STP)

Does anyone know how to export to a STEP or STP file?
Sketchup allows export to a variety of 3D formats - so actually converting from any of those formats to STP would be OK as well, but I was trying to avoid large costs…

SU is a polygon mesh modeler, STEP is a format for saving NURBS-based 3D surfaces and volumes… export as DWG or use a NURBS modeler w/ STEP exporter.

I bouight Punch 2D/3D software for under $100 USD. I just upgraded to V9 for about $50. With this, you can import SU 2015 files. You can export a STEP or IGES or several other formats from Punch 2D/3D. Works great with most models. If they get really complex, then the 32-bit Windows version can choke while exporting STP file. They have a 64-bit Mac version though that should handle very big models well. I have only had it choke on my 1 time and I have exported 100s of models to STP this way.


I just bought Punch 2D/3D in order to convert .skp to STEP files. Two files converted fine but one certain .skp file will not convert into STEP. When I save in order to convert, simply nothing happens.

The .skp file is only app. 2 MB.

You’ll probably want to contact the folks at Punch to get that solved.

give ThomThoms CleanUp³ a try and if solids run the Solids Inspector² too.

Punch Forum

I have seen what you describe and have had contact with Encore (company that makes Punch) regarding this. Here is an excerpt of a conversation over email support after I sent them a file that was acting as you describe…

Steve -

The file is way to complex to be converted into a proper step file using the 2MB of memory that a 32 bit program is limited too. We were able to export it in our Shark FX title, which is 64bit, however the step file turns out to be 590MB.

The reason for this is the file is made up of almost 80000 triangular meshes (ViaCAD works in quad meshes) in 24000 groups. The mathematics and linking alone pushes the 4 MB limit of the 64 bit programs. On top of the shear numbers, using the 3D printing Power Pack plug ins (these plug ins can help diagnose issues with mesh models) we found that there are thousands of duplicate facets and open edges among other general issues which adds to the strain on the resources of the program.

The developers are doing some more testing to see if there is any way to simplify the model and if they do come up with a workaround, I will pass it along.


Todd Q.
Customer Service and Technical Support


After understanding the limitation, I was able to work around it by splitting the design.

Good advice.

ok but you can use sketch up and convert to step files. This is what the cnc peaople want for sheet metel?

Your profile indicates you are using SketchUp Free (web) and there’s no provision for exporting .stp files from that. If you use the desktop client version of SketchUp, you could use an extension called PolyTrans 3D File Conversion System for SketchUp which is available in the Extension Warehouse.

Keep in mind that SketchUp Free and SketchUp Make are for non-commercial use only.

Rhinoceros can import SketchUp files (version 8, I think) and export STEP. You could try that. If I remember right, it has a 90-day free trial (a license costs more than SketchUp). It supports very many 3D formats.

I convert to .stp exporting .stl from sketchup, then I import .stl into Freecad and convert to .stp following this tutorial


Do you have this plugin ? (PolyTrans 3D) it seems that there is no this plugin anymore

No. I don’t have it. Keep in mind this was posted more than four years ago.

Today (6-9-2023) I converted an SKP file to .DAE using “export” in Sketch-Up version 17.2.2555 64 bit
Than I used “Open File” in FreeCAD, turning it into .FCStd
Than “select all” and export to .STEP
It works perfectly.

Why does your forum profile say you are using SketchUp 9? There has never been a version 9 of SketchUp.
Screenshot - 9_6_2023 , 10_42_00 AM

Good point Dave,

I had to fill in something, so I made a blunt guess: 9.

17.2.2555 64 bit is correct though.


Please correct your forum profile.

This post was flagged by the community and is temporarily hidden.


I tied to find a place where I could replace “9” by “17.2.2555 64 bit”.

I don’t know how to do that.