String Action Gauge

  • 158 Reviews
  • Write a review

Fast, accurate measurements for setups. Our String Action Gauge is a "Swiss Army Ruler" for setup adjustments on any stringed instrument.

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Item # 0670
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Item # 0670-M
In stock, ready to ship!


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Quantity: 20


String Action Gauge

Dan Erlewine uses this gauge for checking string height, measuring saddle and pickup heights and more.

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Fast, accurate measurements for setups. Our String Action Gauge is a "Swiss Army Ruler" for setup adjustments on any stringed instrument.

This pocket-size stainless steel rule has become a luthier's favorite in busy shops. It's the best way yet to get vital measurements on acoustic and electric instruments.
• String height
• Bridge saddle height
• Saddle slot depth
• Fret slot depth (unbound fingerboards)
• Nut height
• Pickup polepiece height

No more "three-and-a-half-64ths or 3/32" plus one of those little lines." This gauge measures in ways that regular rulers can't. —Dan Erlewine

Developed here at Stewart-MacDonald by Dan Erlewine and Don MacRostie, the gauge features a progressive string height scale: simply slide it across the frets and read the measurement under the string. It's faster to use than any ruler, and stays parallel to the fingerboard—much easier than trying to hold a ruler perpendicular to a rounded fret. The string height markers are graduated from .010" to .140" on the inch model, and from 0.25mm to 3.50mm on the metric version.

The back of the gauge has a time-saving fractional/decimal/metric conversion chart.

The String Action Gauge is made of durable stainless steel with precision-etched markings, and fits right in your pocket.

Tip: You can use the gauge to set router depth, instead of a shop ruler. It sits solidly on your router base, with the scale right where you need it.

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 Action Gauge

How to determine string action with the String Action Gauge.

Product Instructions

Metric String Action Gauge

How to determine string action with the Metric String Action Gauge.

Ratings & Reviews

String Action Gauge

  • Based on 158 Reviews
Displaying 13 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
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Praktisch und schnell

By conrad from Germany
(Customer's Reviews) Monday, April 18, 2011

Muss man im Gitarrenkoffer haben!
Zum Prnfen und einstellen. keine Probleme. Gut ablesbar.

Amazing tool!

By Heinrich de Beer from Polokwane, South Africa
(Customer's Reviews) Wednesday, April 13, 2011

When I saw the pictures I thought it was just silk screened onto the steel, but when I got it I saw that it's actually sunk into the steel! amazing detail and extremely accurate, will last a lifetime

It helps

By useful tools from Springfield, Il
(Customer's Reviews) Monday, April 11, 2011

I haven't used this in every place that I will, but checking the string height or the neck straightness on the 8th fret is still more difficult than reading one of the digital caliper.

String Action Gauge a worksaver !

By JB Bass from Brick, NJ
(Customer's Reviews) Friday, April 08, 2011

This little multi purpose ruler is just what the doctor ordered for bass and guitar setups. A real timesaver that rests on the frets for more accurate measurements. Well worth the money.

String action gauge

By Froggy3018 from Aberdeen, NC USA
(Customer's Reviews) Thursday, March 31, 2011

How can anyone truly measure action without one of these? Buzzing? You'd be lost without one.


By Adam G. from Langhorne, PA
(Customer's Reviews) Thursday, March 31, 2011

Like everything I've purchased from StewMac, this gauge is precise and high quality.

String Action Gauge

By Rick A. from Kansas
(Customer's Reviews) Sunday, March 27, 2011

While not a luthier, I do want to be able to assess a guitar's action, fretboard condition and setup characteristics, whether I'm buying a guitar or maintaining my own. This is a great tool that provides a quick, accurate measurement of string height. It's a must-have tool in my shop.

My recommendation for taking it to the next level - reproduce the scale in reverse order on the opposite edge or on the back so the gauge can be used from both sides of the neck and you can measure the high-E string at the first fret without looking through 5 strings.

love love love this gauge!

By smashedguitars from San Antonio, TX
(Customer's Reviews) Thursday, March 24, 2011

worth the money, so much easier to use then other methods in my humble opinion...

String gauge

By Douglas Kratz from Malvern, Arkansas
(Customer's Reviews) Friday, March 18, 2011

I've used rulers for years to set string height with so so results. The string gauge takes all the guess work out of setups. I should have bought one of these years ago.

String Action Gauge

By Giovanni from Milan Italy
(Customer's Reviews) Wednesday, March 16, 2011

A must have, very useful.

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Shown on page 16 of our latest catalog.