What is a screw?
A screw is an inclined plane wrapped around a shaft or cylinder: it moves itself when rotated. A screw helps change the direction of effort; a force applied on the screw causes the screw to apply a force on whatever material it pierces through. The circular motion of the screw changes to forward motion.
How are screws used?
The force produced by screws help hold objects together. Screws help keep buildings, bridges, cars, and many other objects from falling apart.
Where are screws found?
Many objects have to be held together. If we want things to stay together, we need screws. Small screws can be found in many household appliances and office supplies, such as blenders and calculators. Large screws can be found outside, such as those in buildings and in bridges.