7. Don’t be surprised if a small
amount of wood sticks to the original
nut when you remove it from the
guitar. 8. The dried glue that held
the original nut in place. Using a
razorblade or scraping tool, carefully
remove the old glue from the nut slot.
9. The nut slot after being scraped
and blown clean.
Clean out the Nut Slot
The nut is usually lightly glued into
the slot. A small amount of wood
may lift up with the nut when you
remove it (Photo 7). Don’t panic,
that’s normal. Once you’ve removed
the nut, you need to scrape out any
residual glue from the slot.
1. Identify any spots of dried glue
and scrape them out using a
shop razor blade or scraping tool
2. After scraping out the glue, brush
or blow out all the debris from
the nut slot, so it’s clean and
ready for the new nut (Photo 9).
10. Sand the thickness of the bone nut blank so it fits snugly in the nut slot. 11. Check the
blank thickness during the initial sizing process. 12. The nut blank is ready to be trimmed for
length. 13. Pencil marks indicate the fretboard edges. 14. Sand off the blank’s excess length.
You can also do this with a small hobby saw. 15. Check the blank’s edges against the fretboard.
Install a New Nut
Once you have a clean slot, you are
ready to fit and install the new nut. At
our shop, we use a Plek machine—a
computer-controlled fret-dressing and
cutting device—to set the string spacing
and cut the nut slots. That said, you can
do everything by hand—the way luthiers
have for centuries. (For a complete explanation
of how to measure, cut, slot, and
install a nut, see “DIY: How to Convert
Your Axe to a Baritone,” March 2012.)
1. Carefully measure the nut slot and
then shape the bone nut blank to fit
into the slot, starting with the blank’s
thickness. Go slowly and measure
frequently. (Photos 10 and 11).
2. Once the blank fits into the slot
(Photo 12), it’s time to trim off
the excess length. With the nut in
the slot, mark where it reaches each
edge of the fretboard. These marks
indicate how much bone you need to
remove (Photo 13).
3. Trim the nut’s length. You can
sand it down to the pencil marks
(Photo 14) or use a small hobby
saw to cut the blank to size. Take
your time and check your progress
frequently (Photo 15).
16. The blank’s edges
are now flush with the
17. Mark the nut to trim
its height by sliding a
pencil sideways along the
frets. The top line results
from placing the pencil
flat on the frets. Draw the
lower line by tipping the
pencil down and sliding
it along the 1st fret. You’ll
remove material from the
top of the blank down to
the upper line. The lower
line roughly indicates
where the nut slots will
18. Sand the blank down
to the upper line.
19. Sized to its rough
height, the nut begins to
20. Use the original nut to
determine the location of
the 1st and 6th strings.
21. A hobby saw that
has been ground to a thin
blade for cutting nut slots.
4. When the blank’s edges are flush
with the fretboard (Photo 16), the
next step is to trim the nut height.
Lay a pencil on the frets and move
its point up against the nut. While
resting the pencil on the frets, slide
it sideways, moving back and forth
with the tip marking the nut. The
resulting line marks the top of the
nut—you’ll remove material from
the blank to this line.
Next, repeat the marking process,
but this time tilt the pencil
tip down and slide along the 1st
fret (Photo 17). This second line
roughly indicates where the bottom
of the nut slots will ultimately be,
once they’re cut.
5. Sand or file the top of the nut
blank down to the upper line
(Photo 18). Once you’ve sanded
down to the top line, insert the
blank into the slot and admire your
work: Now it’s beginning to look
like a nut (Photo 19).
6. If you liked how the original nut
positioned the 1st and 6th strings
relative to the fretboard edges, simply
transfer this distance to the new nut.
Place the original nut at a right angle
to the blank and mark the center of
the 1st and 6th string slots onto the
blank (Photo 20). The spacing of the
remaining four string slots is calculated
from these two points.
7. Calculate the interior string spacing.
At Glaser Instruments, we use our Plek
machine to space and cut the string
slots. The easiest way to set the string
spacing manually is to use the String
Spacing Rule, a handy metal ruler from
stewmac.com that automatically determines
the proportional treble-to-bass
string spacing. It comes with simple
instructions that guide you through the
procedure, which is quick and easy.
Tip: Again, for detailed instructions
on how to cut a nut manually, see
“DIY: How to Convert Your Axe to a
Baritone,” March 2012.
To take its measurements, the Plek
machine requires that all six strings are
on the guitar. To cut shallow guide slots
that hold the strings in place during the
initial measuring phase, we use a hobby
saw that has been ground to a fine edge
(Photo 21). Ultimately, we remove the
strings from the nut and the Plek cuts
new slots, after its software calculates
the optimal string spacing, splay, and
slot depth for a particular fretboard.
22. Cut the shallow guide slots for strings 6 and 1. The spacing of the four interior strings is calculated
from these two points. 23. With the exterior strings in their guide slots, position strings
2–5 using the String Spacing Rule.
String spacing—whether done by
hand or machine—is always based on
subdividing the distance between the
1st and 6th strings. Using the marks
transferred from the original nut, cut
shallow guide slots for strings 6 and 1
From these two points, calculate
the string spacing for strings 2–5 using
the String Spacing Rule. Once the
strings are spaced to your satisfaction
(Photo 23), it’s time to cut the slots.
24. The Plek performs computer-controlled
fret leveling and several other operations,
including cutting string nut slots. 25. Filing
sharp edges from the nut. 26. Polishing the
nut with abrasive paper. 27. The finished bone
nut after being filed and polished. 29. Burnishing
the nut slots. 29. Before gluing the nut
in place, check the string height at the 1st fret.
When you depress each string at the 2nd fret,
you want a small gap between the 1st fret and
that string. This gaps allows the open strings
to vibrate freely.
8. Cut the nut slots. Our Plek holds
the guitar inside a chamber that
houses sophisticated measuring
devices and a computer-guided cutting
tool (Photo 24).
After securing the guitar in the Plek,
we take several measurements to program
into the software that controls the cutting.
This software plots a nut’s many
specifications, including string spacing,
string splay, slot depth, nut top height,
nut top radius, and string break angle.
Once the initial measurements are
done and the software is programmed,
we close up the Plek with the guitar
inside. The Plek then takes its own
detailed measurements of the fretboard
and action, before shaping the nut and
cutting the slots with a precision bit.
It only takes a few minutes for the
Plek to cut the slots and rough-shape
the nut height an radius.
After the Plek has done its magic,
we put the nut back into its slot to
confirm that everything looks right.
9. Now it’s time to polish the nut and
burnish the slots. Begin by filing
off any sharp edges (Photo 25) and
then sand the nut smooth, first with
80-grit, then 400-grit, and then finally
600- or even ultra-fine 800-grit paper
When you’ve finished filing and
polishing the bone nut, it should look
shiny and feel completely smooth
Next, burnish the nut slots with a
very fine nut file (Photo 28). Be careful
here—you don’t want to change
the depth of the slot, but simply make
sure there aren’t burrs or file marks
in the slot that might catch a string.
Some luthiers gently rub an old string
through the slots to burnish them. If
you do this, pick a gauge that drops
easily into the slot and slides through
it without resistance.
10. The final step is to glue in the
nut. But before you do, string up
the guitar, tune it to concert pitch,
and recheck the string height at the
1st fret, using the tapping technique
described earlier (Photo 29).
30. Getting ready to glue the
nut into the slot. 31. A small drop of super
glue at each end of the nut secures it to the
fretboard. 32. In Nashville tuning, the highest
open string is no longer the 1st, but the 3rd.
Put a small drop of super glue on
the end of an old string or jeweler’s
flathead screwdriver (Photo 30) and
carefully let it seep into the tiny space
between the fretboard and the nut
(Photo 31). You don’t need to do this
all along the nut, just at each end. The
goal is simply to keep the nut from
falling out when you change strings,
and prevent it from shifting sideways
due to string tension or string bending.
Have Fun Being High Strung!
And now you’re done! Your flattop is reborn
as a high-strung guitar. Typically, the saddle
that worked for you in standard tuning will
accommodate the four new octave strings just
fine and offer intonation that’s basically as
good as it was before—sometimes even better.
That was the case with our 512c, which, once
we strung it up with the new nut, took to its
high-strung configuration like a duck to water.
Look closely at this guitar, and you’ll see
that the highest string is now G—the 3rd
string (Photo 32). On a high-strung axe,
every chord form you know is automatically
revoiced in new—and sometimes startling—
ways. Octave displacement, an advanced
composing and improvising technique, is
built into Nashville tuning, and the resulting
riffs, melodies, and chords should offer
many years of creative inspiration.