What is the meachanical advantage of a screw?

The mechanical advantage of a screw is derived from its helical design, which allows it to convert rotational motion into linear motion. This enables a relatively small amount of input force applied at the handle to generate a larger output force along the screw's axis. The pitch of the screw threads determines the amount of mechanical advantage; finer threads yield greater mechanical advantage but require more rotations to achieve the same linear movement. Thus, screws are highly effective for fastening and lifting applications.