© 2019 by GMC Luthier Tools

  • Make a new guitar nut.

  • Mark out the string spacing.

  • File the string slots to depth.

  • Improve action & intonation.


A repeatable accurate luthier tool system that simplifies guitar nut making and string spacing.

The strings are proportionally spaced allowing for a progressive increase in spacings between adjacent strings from treble to bass.

4-options are available:

7.25" / 9.5" / 10"

12" / 14" / 16"

17" / 20" / Flat

9.5" / 12" / 15"


Profile plates are available separately to increase the range of fretboard radii if needed.


Typical Use:

6-String Electric Guitar

12-String Electric Guitar

6-String Acoustic Guitar

12-String Acoustic Guitar

6-String Spacing: 34.6mm - 44.4mm (15 increments)

Although primarily for 6-string instruments, this version has a limited range of alternative spacings as follows:

4-String : 20.4mm-27.1mm (17 increments)

5-String : 27.4mm-35.8mm (16 increments)

7-String : 41.8mm-52.7mm (14 increments)

8-String : 49.2mm-61.0mm (13 increments)


Guitar Nut & Saddle Vice.
Nut Top Profile Template for option selected.
String Action Template for option selected.
Radius Gauge for option selected.
6-String Proportional Guitar Nut String Spacing Guide.
String Position Marking Saw.

Colour Coded Fine Adjustment Wire Gauges

String Spacing Diagram




With standard spacing, the string positions are equal but the space in-between them decreases from treble to bass. This can be quite quite significant for heavy gauges.


With proportional spacing, the distance in-between adjacent strings is the same for all positions.


The advantage of proportional guitar string spacing is easier fretting and less muting of adjacent strings. A disadvantage is that once you've tried this method, you might never revert to standard spacing!.


To get the best proportional spacing for your guitar, we recommend increasing the overall string spacing to the maximum that the guitar will allow. A small increase without encroaching on the fret chamfers is usually achievable.


This system is accurate and repeatable. A specially made string position marker and guiding template ensure the strings are precisely positioned along the nut. This avoids any discrepancies with individual hand marking out of each slot as all of the slots are cut in the same setting.


The most unique feature of this tool is its comparison of the instrument. The jig is set up directly from the guitar.  Different string spacings can be easily experimented with and fretboard offcuts make ideal test pieces for practice nuts.


Should you need to do so, a precise re-make/copy of the nut is simple & quick with the jig already setup for the guitar.


Fingerboard Radii
  • "Hello, I just wanted to shoot you a message and tell you how amazed I am by the product. I own a vintage repair shop and can cut a "good" nut with my eyes closed. This product allows me to do it faster and more accurate even than when using calipers. GREAT PRODUCT!. I don't know how long it took to produce this entire set up but let me say thank you for your time and effort" B.L. , USA.

    “When I got the jig, the quality of the product had already awed me and the feeling only got way better when I used it. Truly, an epitome of the Japanese word "pokayoke" which means mistake-proofing! " J.B. The Philippines.

    “My very first attempt at making a nut came out perfect and it was for a 12-string so there was lots of room for error but the jig worked perfectly”. H.J., Utah USA.