Screw (simple machine) advantage (the ratio of output to input force). Screws are widely used in threaded fasteners to hold objects together, and in devices such as screw tops for containers, vises, screw jacks and screw presses. Other mechanisms that use the same principle, also called screws, don't necessarily have a shaft or threads. For example, a corkscrew is a helix-shaped rod with a sharp point, and an Archimedes' screw is a water pump that uses a rotating helical chamber to move water uphill. The common principle of all screws is that a rotating helix can cause linear motion. The screw was one
Archimedes (crater) in what he thought to be a mid-sized crater in the south of the rim of what is now Plato, between that crater (then as "Lacus Panciroli") and Mare Imbrium (then as "Mare Astronomicum"). The stretch of lunar surface between Archimedes and Autolycus was the site of the crash-landing of the Soviet probe Luna 2. This was the first craft to reach the surface of the Moon, landing September 13, 1959. By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Archimedes. The following craters have