A long-term survival situation will require many skills that the average person just does not possess anymore.
Depending on the situation and how long it lasts, skills that you will need include plumbing, electrical, carpentry, hunting, engineering and many, many more.
You will also need to have at least a general knowledge of how to work with metal.
In fact, every skill or trade mentioned above relies on metal in some way to allow you to build, repair or improve components you use on a daily basis.
While it is doubtful you will ever have to make tools yourself (although if the situation is severe enough, you may), possessing a general knowledge of working with metal will help you understand what is needed to repair or build something.
The instruction on the next page cover the basics of melting brass, which along with aluminum, are two metals you should collect and melt as part of your survival preparation routine.