CAD drawings in SLD format (AutoCAD slides) can be exported to IGES format with the Export or Save as.. function found in Autodesk AutoCAD.
Convert Autodesk AutoCAD slide to IGES 3D exchange format.
We have found one software suitable in our database for this conversion.
Apple macOS / Mac OS X software - convert sld to iges on OS X
Mac version of popular Autodesk AutoCAD software
Convert from sld 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.