CAD, raster to vector conversion tools, vectorizing. Vectorize your scan and convert it to a CAD drawing with RasterVect. There is a free and Pro version of the software

Differences between the free and paid versions: while the free version will convert to solid shapes, the paid version offers conversion to outlines, filled outlines, and so-called “centerlines”. The program provides enough value added on the strength of the “solid shapes” conversion, which I think is the most important one anyway, for it to escape being crippleware and for me to feature it on this blog. Taken from the review article here.