The nut is placed at the end of the fingerboard and controls the strings spacing, distance from the edge of the fingerboard and their height above the first fret.
Nuts can be made from a variety of materials and require adjustment or replacement when wear and tear creates problems.
- Open string buzz
- Slots too big for the strings diameter
- Outer E strings sit too close to edge
- String binding, pinging
- High action at first fret
- Poor intonation
Tapping nut loose
Removing A Guitar Nut
Many nuts are very easy to remove. Using a block of wood to distribute the impact, a small tap of the hammer will pop them loose if they sit with only one side against wood (the fingerboard).
However, it is a different story when the nut sits in a channel. These have support from the peghead and fingerboard. Trying to tap these forward could damage the peghead veneer and nut.
Many manufacturers install the nut on the neck prior to paint work. When that finish is thick it is easily chipped when removing the nut. The best chance to avoid chipping is to score the paint around the sides of the nut and across the peghead with a fresh x-acto blade.
Inlaid (Boxed In) Nuts
Nuts that sit in a channel (inlaid nuts) can be removed in a number of ways, all depending on what technique best suits the situation.
Tapping the nut sideways often loosens to the point that it can be removed by hand.
Pushing nut out sideways
Griping the nut with blunt end nippers is another option but the risk remains that the nut may crack or be damaged by the attempt.
Some nuts have been glued in a very tight channel using un-necessarily strong adhesives, this makes them very difficult if not impossible to remove in one piece. When this is the case it is sometimes necessary to cut a relief kerf in front of the nut (.008 slot) so that it may be tapped forward and loosened. The minor relief slot is difficult to detect and filled by the new nut.
Under some of the most difficult circumstances, the nut must be sawn in half and literally collapsed in order to remove. This is done to avoid damaging the nut slot or peghead.
Installing A New Nut
Pre-slotted and shaped
Ready made nuts are available for installation on many instruments, however, adjustments to the slots must still be made. Slots must be filed to insure their width and depth create correct string height.
Using nut files to cut string slot width and depth
This is done using gauged Nut Files which are made specifically for cutting nut slots. The use of inappropriate tools can quickly ruin the nut and cause buzzing.
Made From Scratch
Nuts are often made from scratch when a different material is desired or a ready made nut of appropriate size is not available.
Most material is available in blanks and are shaped accordingly.
I like to tackle it in this order:
- Sand blank to correct width for slot
- Sand base to sit properly in slot (some are angled)
- Sand basic height
- Mark E to E string spacing
- Shape sides of nut to proper width
- Cut preliminary string slots
- Sand final shape
- Polish material
- Install and cut final string depth
Ivory nut being shaped
The most difficult stage in making guitar nuts from scratch is probably spacing the strings properly. The initial cuts are extremely important. I would recommend starting with a razor saw (small kerf) to make the initial slot and then increase the width in steps to keep slot perfectly centered.
Adjusting String Height
It is important to have the instruments saddle height and truss rod set properly prior to cutting the string depth in the nut. Cutting a slot too deeply will place the string against the first fret and result in buzzing.
The depth of the slots in the nut determine how closely the string comes to the frets, particularly the first fret. It is critical that the string have ample room to vibrate without contacting the first fret or you'll have an annoying open string buzz.
Adversely, nut slots that have not been cut properly can leave the strings higher than necessary above the first fret. This creates discomfort and higher action. A minor adjustment (say .020) can make a very noticeable difference.
High action at the nut also sharpens intonation.
Each string slot should just slightly exceed the diameter of it's string. If the slot is smaller than the string it may bind and create tuning problems. (And that annoying pinging sound when tuning up.)
If you've ever had to lift a string from a nut slot when changing strings it's a sure sign the slot is too small.
When changing string gauges, an increase in string diameter sometimes require an adjustment to the slots width.
The slots must also be angled correctly. If the angle is too steep the string may actually rest on just a small portion of the slot causing premature wear as it is sitting on a small peak.
On instruments with minimal peghead angle the angle is especially critical for a clear, clean sound. A poorly angled nut slot can create a buzz like sound that can often be silenced if downward pressure is applied to the string behind the nut (over the peghead). This is often a sign that the string is not contacting the nut slot properly. The sound very closely mimics the sound of the string hitting the first fret when the slot is too deep.
Nut Height/Final Shape
Once the slots have been deepened I may remove material from the top of the nut, if need be, to avoid having the strings deeply buried in the nut. I want the slots deep enough to keep the strings from popping out when plucked but not so deep that they're buried.
Raising Action at the Nut
There are good reason's to salvage an original nut if possible. First of all vintage instruments often have lovely ivory and ebony nuts that are just too nice to scrap.
And of course, it is cheaper, especially if you have an instrument for which no pre-made plastic nut is available. Making a bone nut for a $100 guitar would not make much sense.
My method of raising the nut is to laminate matching material to the bottom of the nut. I use the term laminate and not shim because it is glued to the nut and can only be removed by sanding.
How about filling low slots and re-cutting? Superglue and baking powder have been used to fill nut slots that have been cut too low. I do not like the tone I hear from this method and prefer to raise the nut as a whole and re-cut.
Shims are placed beneath the nut and are often destroyed if the nut is ever removed again. I have seen the made from wood veneer, paper even pieces of credit cards. In my opinion, they look awful. When laminating material to the base of the nut it becomes permanent and more difficult to see. The nut can then be removed just as any other without having to make a new shim.
Securing a Loose Guitar Nut
If a nut pops loose I recommend using a couple of drops Elmer's or wood glue to reattach it. The use of permanent adhesives can create problems should the nut need to be removed for future repairs.
A small dab between the end of the fingerboard and the nut will do the trick and permit easy removal that does not damage the bottom of the slot when removing.
Lubricating Nut Slots
On occasion it is helpful to lubricate the nut slot to reduce friction, binding and pinging. Because acoustic guitar usually have light colored nuts, using white graphite is often preferred to pencil lead graphite.
Acoustic Guitar Repairs
- Action / Set Up
- Bridge Plate
- Bridge Pins
- Buzzing - Noise
- Care / Maintenance
- Convert Rt. to Lt.
- Fret Replacement
- Fret Types
- Neck Damage / Issues
- Neck Angle
- Neck Resets
- Part Glossary
- Strap Buttons
- String Changing
- String Choices / Effects
- Truss Rod
- Tuning Machines
- Tuning Troubles