Leonardo da Vinci’s screw-based lifting machine was a screw jack.
A screw jack raises or lowers a load by turning a threaded screw. The rotation converts relatively small circular effort into a strong upward force, making the mechanism suitable for lifting heavy objects. Leonardo studied screw-based lifting devices as part of his wider investigations into machines, force, and mechanical advantage.
The screw jack concept belongs to a long history of lifting technology. Ancient and medieval engineers already used screws, levers, pulleys, and wedges, so Leonardo did not create the general principle from nothing. His contribution was to analyze and draw mechanisms with unusual precision, showing how components could be arranged for practical work.
A screw jack is different from Leonardo’s separate helical water-lifting design, commonly called the Archimedes screw. The water screw moves liquid through a rotating helix, while a screw jack lifts a solid load through a threaded vertical member. Leonardo’s notebooks include many machine studies, and not every illustrated mechanism can be tied to a surviving manufactured prototype.