String Action Gauge

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Item # 0670
In stock, ready to ship!




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


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String Action Gauge

About This Item

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.

StewMac's String Action Gauge has two models (sold separately) for measuring in inches or millimeters. 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.

Metric String Action Gauge

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

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  • 4.89 average rating from 202 reviews
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saves the guesswork!

(Customer's Reviews)

I bought this for basic setup work (I do all my own setups and for a few friends). A quarter to measure string height, and a business card to measure neck relief works ok, but if you want to do a setup with particular specs, this little gem can get you there. No guesswork. You'll also have known established measurements to reference (and the ability to accurately check them) if you suspect something has changed. With some time and patience, you can really get the best playability with an accurate tool like this. Great tool, and well worth the price!


Works like a charm

(Customer's Reviews)

This tool will save time and ensure accurate set ups


Everyone should have one

(Customer's Reviews)

I own a mix of 29 guitars. If I had to pay for a set up on all of them I'd be in the poorhouse. If I know that there's nothing majorly wrong with my axes, the thing that I can now do easily is to check string height. I used to do it with a 6" metal ruler but mu hands are a bit too shaky. With the string action guide, it's super easy to read thew action on my guitars. My main luthier is always surprised to see me. He thinks that I ran off and found a new luthier.

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StewMac PDF Catalog, page 16 See String Action Gauge
on page 16 of our StewMac Catalog PDF

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