The Screws are a type of mechanical fasteners with a threaded shaft that is intended to screw into a component. Wood screws and self-tapping screws, for example, have a tapered shaft with sharp threads crafted to slice a mating thread in the section to which they are fastened. They also contain system screws, which look a lot like bolts that have the whole shaft threaded. The Screws sometimes rely on thread friction to stay firmly fastened. In addition, the radial expansion of the cavity creates much of the tension in the case of a self-tapping screw.