What is the role of a screw in the first place?

The main job of a screw is to “fasten things together”. But it's a wonder that you can fasten things together just by turning and screwing it in, isn't it? Actually, every shape of a screw has a meaning, and it is a condensation of many wonderful technologies! For a detailed explanation of screw fastening, see here

There is another important role that screws play. That is, they can be “loosened”. If you just want to connect things, there are other methods such as welding, but the feature of screws is that they can be loosened and removed. By removing screws, you can carry out repairs and inspections, and you can also recycle them.

It is said that without screws, there would have been no industrial development, and they are called one of the greatest inventions for humanity. Screws are very small, but they play a big role in protecting our lives!