STP/STEP is a fairly common product data CAD format so it is likely many 3D/CAD programs can import it and then further export to some other 3D format, like the 3DS from 3D Studio Max.
Convert ISO-10303 STEP product data to 3ds Max (3D Studio MAX) graphics.
We found 10 software records in the database related to .stp to .3ds file format conversion.
Microsoft Windows software - convert stp to 3ds on Windows
A widely-used 3D animation application from Autodesk
Convert from stp file format
The tables with software actions are a good pointer for what a certain program does with various file types and often may give users a good hint how to perform certain file conversion, for example the above-mentioned stp to 3ds. However, it is not perfect and sometimes can show results which are not really usable because of how certain programs work with files and the possible conversion is thus actually not possible at all.
A 3D model converter
A 3D modelling application
A 3D CAD translation softwate
3D viewer and converter with huge file type support
A converter for 3D formats
A family of 2D/3D CAD software products for Windows
Apple macOS / Mac OS X software - convert stp to 3ds on OS X
A 2D/3D CAD software for OS X
On-line services software - convert stp to 3ds on web
A commercial online CAD converter
An online CAD conversion service