I THINK (but am not sure) that "screw" referred to the propulsion of a ship in Ye Olde Days [cleverly avoids giving an actual date]. I seem to remember that Fulton (he of steam-power fame) happened to see a ship's screw that had been broken off and hence was shorter, and this gave him the idea for his invention.

I know I'm leaving out loads of details and may be getting it a bit wrong, but I believe that "screw" was the term used in relation to this propulsion mechanism, which Fulton then improved upon.