String Spacing Rule

  • 122 Reviews
  • Write a review

Get accurate string spacing without calipers, calculators or shop rulers.

Read more

String Spacing Rule

Item # 0673
In stock, ready to ship!


Total: $0.00
Quantity: 20


String Spacing Rule

Dan Erlewine shows how to use the String Spacing Rule to quickly locate the strings on a guitar nut. He also explains the problem with using equal spacing.

Subscribe to StewMac's channel on


Get accurate string spacing without calipers, calculators or shop rulers.

Our laser-etched stainless steel String Spacing Rule quickly finds the right spacing for just about any stringed instrument. It does all the math for you: proportional slot spacing automatically compensates for string diameters, from treble to bass, so the thicker strings won't seem crowded to the player.

The problem is: if you space the strings equally, they don't feel equally spaced. The thicker bass strings seem crowded together. Each gap between strings has to be slightly different to feel right to the player. How do you calculate this? The String Spacing Rule takes care of it, for guitars, basses, mandolins, and banjos.

Fast. The String Spacing Rule is slotted so you can quickly mark the string positions onto the nut. Use a scribe instead of a pencil, and it creates extremely accurate starter grooves for your nut slotting files.

Easy to use. Mark the two outer string positions onto the nut. Slide the rule over the nut to find a set of slots that matches your two marks. Now just scribe or pencil the string positions onto the nut! No measuring, dividing or calculating — the rule does the math for you.

Accurate. The rule's slots are laser-cut in a continuous scale that wraps around both edges of the rule (our thanks to luthier Kevin Ryan for creating this tool). Proportional slot spacing subtly compensates for the diameters of the individual strings, from treble to bass, to give the right feel and playability.

Not just for nut slotting. You can use the String Spacing Rule to notch Tune-o-matic bridge saddles, to lay out bridge pin holes, and when notching archtop guitar, banjo, mandolin and violin bridges.

The String Spacing Rule is made of laser-etched flexible stainless steel that conforms to flat or arched surfaces. Instructions are included.

The String Spacing Rule is included in the Essential Nut Making Tool Kit, which has all the basic tools you'll need for shaping, string-spacing, slotting and fitting string nuts like a pro.

Trade Secrets! Newsletter

Using the String Spacing Rule for guitars and mandolins

Erick Coleman uses Kevin Ryan's proportional string spacing rule for more jobs than Kevin ever expected: 12-strings, mandolins, bridge saddles... Plus: an explanation of the difference between equal spacing and proportional spacing.

Product Instructions

Making a Nut, Step-by-Step

Dan Erlewine, of Stewart-MacDonald's R&D Team, walks you through making and installing a new nut.

Product Instructions

String Spacing Rule Instructions

The String Spacing Rule locates string positions so that heavier strings get the wider spacing they need.

Ratings & Reviews

String Spacing Rule

  • Based on 122 Reviews
Displaying 5 of 13 1 2 3 4 5 6 7 8 9 10 11 12 13
Write a review

This is so simple and a time saver too

By GavinB from Perth, Australia
(Customer's Reviews) Sunday, October 07, 2012

Love it, saves time and is simple to use.

Gotta have

By Tmc from Trinity Ala
(Customer's Reviews) Friday, October 05, 2012

If you do nut replacement on various instruments Fiddles, Guitars and Mandolins, you gotta have one, cuts down on time and is accurate..

Tudo de bom

By Rodrigo Gomes from Brazil
(Customer's Reviews) Thursday, September 27, 2012

Agora npo quebro mais a cabeta fazendo cßlculos matemßticos!

Very easy to use

By LoveThoseSixStrings from Indiana
(Customer's Reviews) Friday, September 14, 2012

Following the online directions, I made a perfectly-spaced nut the very first time I used the rule--which was a good thing, considering the price of the blank! This tool allows you to quickly and easily customize string spacing to suit your individual playing style. I cannot recommend it highly enough.

Great easy product

By Great product from Kihei, hawaii
(Customer's Reviews) Friday, September 14, 2012

This is a great tool, saves time and money as well as fristration.

Amazing rules

By Ivan Souza from England
(Customer's Reviews) Monday, September 10, 2012

do you want a perfect job? a great nut then you must get one you won¦t be sorry after , you will know exacly and fast where the string should be positions, " if you want work as PRO you need get a PRO tools!

The Rule that rules.

By Tom O' from Jersey. C.I. British Isles.
(Customer's Reviews) Tuesday, August 28, 2012

Ooh it's very well manufactured.
Why take a chance and ruin an almost completed nut when this little beauty eliminates that chance..?! I wish i had bought one years ago..

Stop waiting and get it

By Hagbone from Montrose PA
(Customer's Reviews) Monday, August 20, 2012

Fussing with slot layout isn't rocket science, but it is tedious. The cool thing about the spacing rule is that it's quick, and it frees your brain up by giving you the absolute confidence that you're locating the slots dead-on.

The laser cut openings work perfectly. I work with severe radius nuts (as much as 5 inches), and this thin spacing rule flexes easily to accommodate the layout.

This is just one more example of what I've found with StewMac tools and rigs - a high quality tool that once you have it, you wonder how you got along without.


By sonic from Hamburg
(Customer's Reviews) Thursday, August 09, 2012

I wanted to make a bone nut from scratch with limited knowledge. I knew I needed some tools to finish the job and this is one tool that helped me get through a part of the process. I understand you need the right tools for the job and this is one of them. Once you reach this point haveing the right tool makes all the difference. It is one question you do not need to go into brain overload over.

5 star tool!!!

By Jo+úo Paiva from Azores, Portugal
(Customer's Reviews) Wednesday, August 08, 2012

The best tool of its kind

Displaying 5 of 13
1 2 3 4 5 6 7 8 9 10 11 12 13

Shown on page 6 of our latest catalog.