A spring is a rather elastic object that is normally used to store mechanical energy. In everyday usage, this term is used when referring to coil springs. These little things are usually made of spring steel. Of course, there are a lot of spring designs but, their manufacturing process is practically the same.
Springs can be made of hardened steel, non-ferrous metals such as titanium and bronze and sometimes even plastic. There aren’t many machines that make spring, but of the few there are, the most widely-known one is the auto-coiler.
You can see in the Spring manufacturing process video below how it works – check it out!