A Fender nut is a small, steel piece that’s used to safe the strings of a Fender guitar to the neck. You will need to arrange the Fender nut accurately as a way to make sure that the guitar performs in tune and that the strings are on the right top above the fretboard.
There are a couple of other ways to arrange a Fender nut. One widespread technique is to make use of a nut file to file down the slots within the nut till the strings are on the right top. One other technique is to make use of a shim to lift the nut up or down.