Autodesk Inventor supports export to plenty of other 3D modeling / CAD formats, including IGES 3D exchange format (.igs, .iges). So the easiest and most reliably way to convert .idw to .igs would be to use the original tool. Some viable alternative would be to use some other, 3rd party 3D modeling or CAD tool with support of Inventor's formats.
Convert AutoDesk Inventor drawing to IGES 3D exchange format.
We have found one software suitable in our database for this conversion.
Microsoft Windows software - convert idw to igs on Windows
Autodesk Inventor is 3D solid modeling and design tool used to design and simulation 3D digital prototypes.
Autodesk Inventor shares 2D data from the AutoCAD and 3D design data from other Autodesk's applications. Autodesk Inventor is available for Microsoft Windows.
Convert from idw file
|Yes, Autodesk Inventor supports idw file conversion as a source file type.||Yes||Yes||idw editor||Yes||No||No||No|
to igs file
The table with program actions contains information about what each program is capable of doing with their files. This may be a good pointer for further searches for certain file conversions and help you find the converter you are looking for if our search result is insufficient for you. However, it is far from perfect and may sometimes show results which are not really usable because of the nature of the software handles the files. So a conversion that appears as possible, just because of matched actions, may in fact not be possible.