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 3 of 16 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
Write a review

Must have tool for any guitar work.

By Isabel Ambrocio from Mexico
(Customer's Reviews) Saturday, August 03, 2013

This is a must have tool if you do anything from just playing to full custom guitar building. Need to know what size drill bit for those tuners with screws that are not designed for the job, well pull out your magnifying glass and your string gauge tool and measure the shaft of the screw and then the width of the threads and your drill bit will be something in between. The way this tool is designed you can measure anything from nuts, to string hight, to pilot holes with ease. This tool is well worth the cost. Who ever designed this tool was from the world us old timers come from, a world not from evil marketing but from experience.

One of the most used tools on the bench

By Billy M from Baker, LA
(Customer's Reviews) Thursday, August 01, 2013

Invaluable for setting action heights, measuring fret slot depth, etc. Stays on a magnetic tool holder strip right above the bench because I use it frequently.

A must have

By GPosada from Colombia
(Customer's Reviews) Monday, July 15, 2013

This tool is a must have in order to check your own sting action. Combined with the Radius Gauges, performance is improved amazingly.

Every guitarist should have one of these..!!!

By versatone from Washington DC
(Customer's Reviews) Friday, July 05, 2013

These will help you maximize your guitar's playability. You can, and should, do this yourself - there will be plenty of things that will be beyond your ability that will need to go to your local professional repairman, but this you can do yourself.

Must have item

By E from California
(Customer's Reviews) Friday, June 28, 2013

If you do any of your own setup, you must own one of these. You'll wonder why you didn't buy one years ago.

String Action Guage

By rbfh1234 from Washington, Illinois
(Customer's Reviews) Sunday, June 23, 2013

Amazed how handy this gauge is to have around. Already used it on my guitars, mandolin, ukuleles, violin, mountain dulcimer, and just today on a psaltery that I am refurbishing. So much easier to use and read than a conventional ruler. If I ever lose this one, I would have to buy another.


By jbass71 from Baltimore, MD
(Customer's Reviews) Wednesday, June 19, 2013

Best $20 i ever spent. so helpful i can't even tell you. GET ONE!

Must-have for setups

By Greg, Ruby-Ryder Guitars from Mesa, Arizona
(Customer's Reviews) Friday, June 14, 2013

This tool makes action adjustment a breeze. Another tool I buy multiples of and give away as gifts. I have both the standard and metric versions.

Want accurate string action?

By Jorge Pulido from NYC
(Customer's Reviews) Thursday, June 13, 2013

This is the best measuring tool for setting your string action. Sits across a few frets to avoid rocking. A must have tool.

The One Ruler to Rule them All.

By Mack L. from California
(Customer's Reviews) Tuesday, May 28, 2013

All jokes aside this ruler is a must have for every Luthier or Tech. There are endless uses for this in the shop. Pull the trigger and you wont regret buying this. This is my most used tool in the shop.

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Shown on page 16 of our latest catalog.