nut

A nut, on a stringed musical instrument, is a small piece of hard material that supports the strings at the end closest to the headstock or scroll. The nut marks one end of the vibrating length of each open string, sets the spacing of the strings across the neck, and usually holds the strings at the proper height from the fingerboard. Along with the bridge, the nut defines the scale lengths (vibrating length) of the open strings. The nut may be made of ebony, ivory, cow bone, brass, Corian or plastic, and is usually notched or grooved for the strings. The grooves are designed to lead the string from the fingerboard to the headstock or pegbox in a smooth curve, to prevent damage to the strings or their windings. Bowed string instruments in particular benefit from an application of soft pencil graphite in the notches of the nut, to preserve the delicate flat windings of their strings. Etymology The word may have come from the German Nut (pronounced "noot"), meaning groove or slot. The nut, however, is called a de:Sattel ("saddle"; also Obersattel) in German, whereas the part of a guitar known as the saddle in English, the surface of the bridge on which the strings rest, is called a de:Stegeinlage or Steg, in German. In French, the nut is known as a :fr:sillet, which, like German, can also translate to mean saddle. The Italian term, capo tasto (or capotasto; "head of fretboard"), is the origin of the capo. Variations Not all string instruments have nuts as described. The nuts on some instruments are notched deeply enough that they are just string spacers. These instruments use a zero fret—a fret at the beginning of the scale where a normal nut would be that provides the correct string clearance. The zero fret is often found on less expensive instruments, as it is easier to set up an instrument this way. However, a zero fret also makes the sound of the open string similar to fretted notes. A conventional nut can make open strings sound slightly different—and for this reason some high-end instruments use a zero fret.