Most of CAD software nowadays support the IGES ASCII format (*.igs, *.iges) and thus can be used to re-saved it to another CAD format. This also goes for the various CAD files, used for example in BobCAD-CAM Mill program.
Convert IGES 3D exchange format to CAD drawing file.
We found one software available in the database for this conversion.
Microsoft Windows software - convert igs to cad on Windows
A CAD-CAM software for CNC Milling
Convert from igs file format
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.