A screw is one of the six simple machines. A simple screw is a helical inclined plane. A screw can convert a rotational force (torque) to a linear force and vice versa. The ratio of threading determines the mechanical advantage of the machine.

Archimedes' screws and worm gears are examples of this machine.

See also

• Screw (disambiguation)
• Screw - the threaded fastener
• Archimedes' screw

Simple machines