A Fender nut is a small, steel piece that’s used to safe the strings of a Fender guitar to the neck. It is very important arrange the Fender nut appropriately so as to be sure that the guitar performs in tune and that the strings are on the appropriate peak above the fretboard.
There are a number of alternative ways to arrange a Fender nut. One widespread methodology is to make use of a nut file to file down the slots within the nut till the strings are on the appropriate peak. One other methodology is to make use of a shim to lift the nut up or down.