Hi,
When you export to STEP in alias, you can see from the options it offers, that there is no tolerance stuff. You have some parameters there to fiddle with, and that will dictated by what is downstream.....Generally i dont touch them.
Since STEP is a more widely format used than IGES when dealing with solids, i am assuming that s the case.
Anyway, what you can do before you export, is to shell stich your model, just to ensure you have a WATERTIGHT model. You will find that in the EDIT SURFACE tools. Here is where you can play around with the tolerances you need. Tick the use construction options option, which will be dependent on what is set in your options. MAximum Gap Distance, is what governs your tolerance when you are stitching. If you turn it off, will be presented with a slider to chose whatever value you need as a tolerance, independently of what is set in the construction options.
You can also Export as STL straight out of alias....Do as you require.
Hope this helped a little.
Good luck
