Stereolithography CAD files for 3D printing (.stl) are well supported in various CAD programs and can be used for conversion purposes. However, only geometry from these files can be typically converted.
You can for example save the various parts as 2D drawings in DXF format or something different. Some tools capable of stl to dxf conversion are listed below.
Open STL file Open DXF fileA professional manufacturing data preparation software
A CAD 3D geometry translation software
A CAD and Gerber conversion software
A Mac version of the popular 3D visualisation software
A set of 3D modeling tools
A converter for 3D formats
Creo Parametric (formerly known as Pro/ENGINEER) is a complete 3D CAD software solution by PTC
A CAD/CAM for material working industry
An open source multiplatform 3D CAD/MCAD/CAx/CAE/PLM modeler
A command line converter for 3D format
A 3D mesh converter
A 3D CAD translation software
A CAD drawing and CNC programming system