By Graham Bellerby

Guitars are one of those instruments that a lot of people pick up, a lot of people play, and few people properly maintain. There is a huge difference between knowing that a guitar works the way it does, and knowing how and why a guitar works the way it does. I’m hoping to briefly explain a small fragment of that today as I teach you what to look for before restringing a guitar.
As you hopefully all know, a guitar is a string instrument in the treble range, treble here meaning high-pitched. The tones are made through strings, which are made of various components, including nylon, steel, bronze, copper, and cobalt. These materials are wound, or pressed, into strings of varying lengths, sizes and thicknesses.
These variances are called the string gauge, which is something you need to pay attention to when restringing a guitar. String gauge is measured in centimeters, and as a string’s gauge approaches and passes a centimeter in thickness, the truss rod of a guitar needs adjusting accordingly.
The truss rod is a long, thin metal cylinder that runs the length of a guitar’s neck, and is implemented to prevent the neck of a guitar from warping. The truss rod needs adjusting occasionally when changing strings, especially when switching thicknesses. Switching from .46cm to .56cm will require a tightening of your truss rod in order to maintain the shape of your guitar’s neck; however, if you switch the other way, say from .56cm to .46cm, you will need to loosen your truss rod as not to create unnecessary tension on your guitar’s neck.
You might be asking right now “why would I need different thicknesses?” Well, this is one of those things, as with a lot of aspects of music, that is the same for everybody. Some people choose to drop the tuning of, or detune their guitar to something below the standard tuning. This reduces tension of the strings, which can lead to a floppy, or “tinnish” harsh sound. People who do this tend to want a thicker gauge string, so they can maintain all of their tonal quality while playing in the tuning they desire.
On the flip-side of this, some players choose to tune their guitar above the conventional tuning in order to achieve certain timbres and sounds. If you do something along these lines, you will need a much thinner gauge of string in order to prevent tension issues, and unnecessary string breaks. Anyway, I really hope you learned something, and that you consider and check these things out before you buy guitar strings and begin re-stringing.