There are six simple machines. They make it easier for us to do work. The screw is one kind of simple machine. Screws help us hold things together. A screw is a long post that is wrapped with metal threads. A screw is actually a kind of inclined plane. It is an inclined plane that is wrapped around a cylinder. If you follow the threads on a screw, they will form a long ramp from the bottom of the screw to the top of the screw. The threads on a screw may be close together. .....