Measure the following parameters carefully, using an accurate ruler or calipers, to within .03 inches or .8 mm: length, width, height and "E-to-E" string spacing. The diagram above illustrates where the measurements should be taken.

Measure the length and width at the base of the nut. Some nuts taper towards the top and will render an inaccurate reading if measured elsewhere.

Measure the height at the tallest part of the nut, which is not always at the centre of the nut.

For the E-to-E string spacing measurement, measure as closely as possible to the centre of each string slot.

The E-to-E spacing measurement is the most important parameter to match with a replacement nut. It determines the string spacing on the neck, and how close the strings are to the edge of the fingerboard. It is not adjustable; unlike the length, width or height of a nut, string spacing cannot be adjusted to fit.

Should you find a nut that is a little too long, high or wide, you can easily remove the excess material by working the part back and forth along a piece of 600-grit sandpaper placed on a firm, flat surface.

Nut Installation Instructions for acoustic or electric guitar

STEP 1. Remove the strings. Trace around (score) every edge of the nut with an exacto knife to prevent lacquer sticking to the nut and the neck and chipping away.STEP 2. If the nut is not sitting in a slot, usually a light tap with a small block will set it free. If it is sitting in a slot, gently tap it out sideways using a hammer and a screw driver.STEP 3. When it is sticking out the side, pull it out in the same direction with a pair pliers, like you would a tooth. Scrape or file the nut slot free from old glue and finish residue while making sure that slot remains square..
STEP 4. See if the Graph Tech nut fits into the slot, without forcing it. If it’s too thick, place a 100 grit (to start) to 400 grit (to finish) sand paper face up on a flat surface and sand down the bottom and sides of the nut until it fits in the slot snugly but is easily removable.STEP 5. Restring the high and low E strings and tune to pitch to check for correct height. Pushing down on the third note of the low E string should result in a .010" gap between the string and the first fret; high E string should be .006"STEP 6. Once you’ve done the thickness and the height, you just need to sand the ends of the nut so that they are flush with the neck. Just use a pencil and mark the ends of the nut that are sticking out, remove it from the neck and sand it to your marks.

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