Trying to export solid models from Rhino 5 to Solidworks 2019 and every format that I have tried opens up as loose surfaces in Soildworks. There are also misc surfaces that are in the file. See screen shot of the Solidworks file.
Hello - if these are joined in Rhino and the tolerances reasonably tight (?) then via STEP format they should open as solids in SW. Feel free to post a file here or to tech@mcneel.com (with a link back to this topic, please)