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
In stock, ready to ship!




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


Total: $0.00
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 9 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
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Important tool!

By Andre Pinho from Rio de Janeiro, Brazil
(Customer's Reviews) Monday, February 27, 2012

Great item, changed my vision about all instrument's height!

Super Useful Tool!

By KickAxe USA from Rifle, CO
(Customer's Reviews) Thursday, February 23, 2012

This guage is great! I use it on EVERY setup, new nut install, etc. I've got 2 of them. One is worn out a little (hard to see the numbers on it due to LOTS of use). If your doing setups, you GOTTA have atleast one!

Good tool to have

By DT from New-brunswick
(Customer's Reviews) Friday, February 17, 2012

This is a good quality tool to have in your shop. A lot of usefull references on this small piece of metal

Not as good as I'd hoped...

By Bob Gretsch from Dracut, MA
(Customer's Reviews) Friday, February 17, 2012

For the money I think it is not of great quality. Also measuring in 10ths is not as accurate as 64ths. It's only kind of useful. I should have looked more carefully before I bought it.

very usefull

By Lucio from Italy
(Customer's Reviews) Sunday, February 12, 2012

I have a lot of archtop guitars. This tool allows me to adjust the action very quickly and the slope of the bridge.

Action Gauge

By Moriarty Guitars from Dublin Ireland
(Customer's Reviews) Tuesday, January 31, 2012

Bought the imperial version a good while back. Use it all the time for string action measurements, so for that it's 5-stars. Ideally, I'd keep the string action side the same (inch fractions, like how we measure strings) and have a metric ruler on the opposite face.


By Steve Newton from Pembroke, Wales
(Customer's Reviews) Sunday, January 29, 2012

It makes the job of measuring the string height so much faster and clearer.

I have to agree with Martin Fuerstenau though, a version with metric and inches would be indispensable and would get a 10 star rating.

Absolute Money Maker

By Ricki Leigh from Pennsylvania
(Customer's Reviews) Friday, January 20, 2012

Not only do you save time in checking string height specs you can check a customers guitar instantly and get another repair out of it.

Ms Ricki Leigh


By JMOGuitars from Cardiff, UK
(Customer's Reviews) Saturday, January 07, 2012

you NEED this, it's the one tool that I just cannot live without now.

Fantastic setup tool with a little drawback

By Martin Fuerstenau from Unterfoehring
(Customer's Reviews) Friday, January 06, 2012

I live in Germany. That means metric. I read a lot of guitar building books. That means metric and imperial. Therefore I ordered both - the metric one and the imperial one. Thats the drawback. I think it would be great to have metric on one side and inch/fractional on the other side instead of the conversion table.

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Shown on page 16 of our latest catalog.