What machine did Leonardo da Vinci design to cut threads in a controlled way?

Leonardo da Vinci designed a screw-cutting machine for producing threads in a controlled way.

His mechanical drawings include a lathe-like device in which a workpiece could rotate while a cutting tool followed a guided path. This arrangement addressed a difficult manufacturing problem: making regular screw threads with consistent spacing. Screw mechanisms were already known, but accurate production was laborious when done by hand.

Leonardo’s design belongs to the history of machine tools rather than to a single universally accepted modern invention date. Later engineers developed more practical screw-cutting lathes, including machines associated with the eighteenth and nineteenth centuries. The Leonardo drawing is significant because it shows an early attempt to mechanize precision thread production. It should not be confused with a printing press or a general-purpose wood-turning lathe.