Hi Everyone,

I’m looking to get some mass-produced parts from overseas, but the vendors seem to only be able to accept files as STP, STEP or IGS files. I’d never even heard of these file types until they mentioned them. So, I have two questions:

1) What exactly are STP, STEP and IGS files that makes them different from STL and OBJ files?

2) What software can I use to convert my STL and OBJ files to STP, STEP and IGS files? Is there anything readily available?

Any help anyone can offer would be great.

Thank you!


1 Like

Step and igs files are associated more with Cad programs.

Download a trial version of fusion 360 and import your files into the software and export the format you need.

Yes I think those file formats are more universal so they’re used when transfering models. Not sure what software you use but you can usually simply go to save as and choose the desired extension. Simply pick the one they prefer.

Great! I’ll give it a shot. Thank you!


I’ll definitely give that a try.

Thank you!

There are quite a few differences in the file types. One of the biggest is that STEP, IGS files have the scale included. STL files do not.

And STL does not include layers, assemblies, constraints, etc.


You can use freecad https://www.freecadweb.org/?lang=fr to convert your files. It’s a free solution and you can use it to convert your files .

Best Regards

You can’t just import a STL and export as a STEP in a single click in any software, you have to redraw the whole model and then save as a STEP. We can help you out with that if you want but its not always an easy job.

Thank you!

I import stl files all the time into Fusion 360 and export as a step or iges. Most Cad software on the market allow that. 3d software like blender, 3ds max, maya, zbrush, etc can not as they are not Cad specific programs.

I’m just starting to experiment with Fusion 360 now. It looks pretty cool. How much does it cost to buy once the trial version has expired?

depends on the subscription plan. $40 monthly or $300 for a year.


Ok, great.

Now, I just uploaded my model and exported it as both an STEP and IGS file. But the exported files don’t show anything in the way of thumbnail images - they’re also very small. Is that normal?

I tried to reupload them to Fusion as well, to see if they would open, but they seem to be just blank files. I’ve attached a screen grab that has the OBJ file on the right, and the IGS version on the left.

Is there something I’m doing wrong? Or are these file types just not visual?

did you change the system units to match the imported file’s units before exporting?

I did not…

Is the dialog box on the right what you’re referring to? If so, is there a different setting I should be using?

Hey…just wanted to see if my last message came through.

You’ve been very helpful so far. I hope to continue learning from your tips!

Thank you!


No didn’t get your first notification. Yes changing those units should export the design correctly. That may be the reason as to why you were not getting a thumbnail when exporting as the design was exported smaller than what it should have been.

Oh, awesome! I think that worked - I had it at mm instead of inches.

Thank you so much for your help! Would it be okay if I got in touch with you again on here in the future? You seem to know your stuff.

Actually, I spoke too soon. Apparently I exported the file as a F3D file, and THAT worked.

But then, when I tried to export as a STEP file, I got the same results - the export completed, but the file was empty when I tried to upload and open it.

Is there something I’m doing wrong? Do I need to change settings somewhere else?

Try converting the file inside the program to a Brep and then export. https://youtu.be/njbzuzqRLSs