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.

Read more


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.

Subscribe to StewMac's channel on


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

I was looking for such tool long time!

By G23CRCT from Wakayama, JPN
(Customer's Reviews) Thursday, February 24, 2011

Very x 10 useful !! (^_^)

String Action Gauge - "A Winner!"

By FrankV from GA
(Customer's Reviews) Thursday, February 24, 2011

This item works just as described. Easy to see and read, no more feeler gauges,picks, business cards,steel rulers etc. A must have for setups and tuneups.

Thanks StewMac

Wow! Best $$ spent on my guitars.

By kzimmer from Brighton, IL
(Customer's Reviews) Monday, February 07, 2011

If you only own one specialty tool for your guitar(s), this should be it! I use it for not only setting string height but for adjusting the bridge, measuring saddle width, pole adjustments, etc. Anywhere on your guitar that a small accurate measurement is needed, this tool has you covered. Great product!

Great tool

By Dane Paul from Nashville
(Customer's Reviews) Sunday, January 30, 2011

I've used everything from business cards to my wife's quilting ruler. Finally I know exactly what the height is. Looks great too.

A "must have" tool!

By RDL from New Mexico
(Customer's Reviews) Friday, January 28, 2011

An essential tool for set ups.

String Action Gauge

By Big Dave from Troy, Missouri
(Customer's Reviews) Wednesday, January 26, 2011

I have tried several methods of measuring string height. From expensive digital measurement devices to the go-nogo methods. I can say that the String Action Gauge is the easiest, fastest and just best way i have found to do this. I carry it around in my pocket. You'd be surprised how many times a day i reach for it. It's a must have in my opinion

a great tool

By Back Porch Mojo from Southern Illinois
(Customer's Reviews) Wednesday, January 26, 2011

I added another great tool to my arsenal!! This really helps take the guess work out, no more guestimating!!

A Winner

By GOA Guitars from Bris Australia
(Customer's Reviews) Friday, January 21, 2011

Now this is just the greatest little rule ever super smart idea.

A MUST have tool!

By Mikes Guitar Garage from Sydney, Australia
(Customer's Reviews) Thursday, January 20, 2011

This little guy gets used constantly in my shop.

I can precisely talk to a customer about action and relief with the help of this guide.

It also comes in handy for making nut slots, setting pickup and pole piece heights, and I've even used to to measure the height a floyd rose bridge was sitting off the body, as my customer wanted it to sit "EXACTLY where it is now" when he brought it in for a setup.

Just a tip for the Aussies; Although in Australia we use the metric system, I got the Imperial version. Anything to do with measuring guitars, i prefer imperial, as 99% of reference material (DVDs, Books, Factory Specs) are all written in inches. Sure saves time doing the conversions. It takes a little getting used to, but I'm now really comfortable working with imperial measurements.

Incredibly useful tool

By Michael Myers from Maryville TN
(Customer's Reviews) Sunday, January 09, 2011

This tool maybe somewhat deceptively named. I have not only used it to set string action, but pick up height as well. It has really improved my guitars' sound and feel. I just set up my Dbl Cutaway Les Paul last night and it plays better than it ever has. The rest of my 15 guitars play the same way, thanks to this easy-to-use tool.

Once again, Stew-Mac to the rescue and my guitars are now setup professionally (by me). Loads of money saved and the use of this tool is exceptionally easy, even for a beginner. Stew-Mac also included a suggested setup sheet with mine that tells exactly where to start fine tuning my guitars' setup.

This tool isn't one of those cheap plastic ones that tear up within a month, but is heavy gauge stainless steel and will last for years to come. Thanks Stew-Mac! I am one happy customer!

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

Shown on page 16 of our latest catalog.