The screw is actually a modification of the wedge that is used in two different ways:

To fast or press an object onto something

Or

It can raise weights

When you really think of it, the screw isn’t really a simple machine because it depends on another simple machine (lever) to function correctly. The screw was originally found around 200 BC by the Greek mathematician, Apollonius of Perga. Screws can found in places such as jar lids, light bulbs, and chairs. In example of the chair, the screw is very useful because it holds the chair together and prevents it from falling apart from underneath you and also prevents serious injury.