A screw is a type of fastener that is commonly used to hold two objects together by creating a thread that grips the materials. Screws typically consist of a threaded shaft, a head, and a point.
The threaded shaft of a screw is the part that creates the gripping action. The threads on the shaft can be either coarse or fine, depending on the intended use of the screw. Coarse threads are typically used for wood, while fine threads are used for metal and other harder materials.