According to the software used by the client, the suitable file formats for data exhange are the following (in priority order):

Software File format
CATIA MODEL, EXP, STEP, IGES (IGES Settings), DXF, DWG
Unigraphics PRT, Parasolid, STEP, IGES, DXF, DWG
Pro/Engineer PRT,IGES (IGES Settings), STEP, DXF, DWG
IDEAS STEP, IGES (Unigraphics flavor), DXF, DWG
SolidWorks SLDPRT, SLDASM, SLDDRW, Parasolid, SAT
Cadkey PRT
Rhinoceros 3dm, IGES
SolidEdge Parasolid, ACIS, IGES, DWG, DXF
AutoCAD SAT, IGES, DWG, DXF
Mastercam MC9
KeyCreator CKD