Understring Radius Gauges

  • 142 Reviews
  • Write a review

Fast, accurate bridge saddle adjustment.
Each of these unique gauges has an accurately radiused arc on both the top and bottom surfaces, and is shaped to fit easily under the strings.

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Set of 9

Item # 0353
In stock, ready to ship!



17" gauge only

Item # 0352
In stock, ready to ship!


Total: $0.00
Quantity: 20


Radius gauges for guitar work

Dan Erlewine demos the three kinds of radius gauges for setup and fretwork.

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Fast, accurate bridge saddle adjustment.
Each of these unique gauges has an accurately radiused arc on both the top and bottom surfaces, and is shaped to fit easily under the strings.

Use the bottom curvature to determine your fretboard radius, and the matching top curvature becomes a reference for setting string saddle heights for best playability.

Set of 9 now includes new 17" radius for Ibanez guitars!

Find your fretboard radius, and set your bridge saddles to match. They're handy for matching pickup polepiece heights to the arc of the strings, too. Precision laser-cut from .050" stainless steel.

The set of 9 gauges includes:
7-1/4", 9-1/2", 10", 12", 14", 15", 16", 17" and 20" radii.

They'll work for string spreads and fingerboards up to 2-5/8" (66.68mm) wide.

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Ratings & Reviews

Understring Radius Gauges

  • Based on 142 Reviews
Displaying 10 of 15 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Write a review

Great Item!

By Rick C. from Halifax, MA
(Customer's Reviews) Saturday, September 17, 2011

a little pricey but a great tool. Do something about your shipping costs! Terrible! I don't need a huge box and tons of paper for a tiny little unbreakable item.

better in aluminum...

By Drac68 from Copenhagen, Denmark
(Customer's Reviews) Wednesday, September 14, 2011

Well done remaking them in metal-I had a set of 1st gen. rendered in white acrylic, and in time, several of them had broken- this set can take a beating, and makes life easier.

A time-saver!

By Middleton Guitars from Southern California
(Customer's Reviews) Tuesday, August 30, 2011

This is a must-have if you set up a lot of guitars. Makes dialing-in Strat-Style bridges quick and accurate.


By nowakowski from germany
(Customer's Reviews) Thursday, August 25, 2011

alles super gelaufen. versand und ware sehr gut.

Workmanlike and practical

By Maurice Condie from UK
(Customer's Reviews) Thursday, August 25, 2011

These have proved very useful and have saved a lot of time.

Something I had to have

By rolfm5 from Joshua Tx
(Customer's Reviews) Saturday, August 13, 2011

Being someone who likes to do his own set ups, this little set of gauges makes life so much easier when getting the correct radius on the strings. Highly recommended.

Excellent Tool

By Slip'ry Dan Weisberg from San Jose, CA
(Customer's Reviews) Monday, August 08, 2011

The Understring Radius Gauges are must have tools for guitar setup.

I also purchased the StewMac String Action Gauge, and the CruzTools GuitarTech Guitar kit, which I found on Amazon. The CruzTool kit has the wrenches needed to adjust neck truss rods, as well as a metal ruler, feeler gauges, and some other setup tools in a nice case.

These tools allowed me to setup my Tele and my Musicman bass so that they play much better!

I also bought the book How to Make Your Electric Guitar Play Great by Dan Erlewine. You can probably setup your guitar without it by using the Web and the instructions that come with the CruzTool kit, but the Erlewine book puts it all in one place, and gives some setup specs and problem solving suggestions as well.

One area that the book was a little weak on was the topic of Neck Angle. After adjusting my bass guitar's truss rod, I still needed to lower the bridge to get the right string height, but the bridge pieces were as low as they could go. So instead I adjusted the neck angle which solved the problem. Luckily, I found some good info on the web about this.

Awesome tool

By Slash671 from Guam
(Customer's Reviews) Sunday, June 19, 2011

Who would've thought that a simple thing like matching the neck radius to the bridge radius would be a major improvement. This little adjustment made my guitar MUCH more playable! Goodbye fret-outs and dead notes! Thanks Stewmac!

Understring Radius Gauges 

By Andy A from Cincinnati
(Customer's Reviews) Thursday, June 16, 2011

Very helpful tool in setting up a guitar. Especially on a Strat or Tele. Very quick shipment. Stewmac.com is a great place to start collecting tools and getting good information on how to do repairs and stuff. Thanks guys!

Great For Saddle Tops

By Wimsatt Instruments from Nashville, TN
(Customer's Reviews) Friday, May 27, 2011

This is a good tool to find the top radius on your saddles. Just match it to the end of your fretboard. I'd still use a 6" ruler to do individual string height, especially on boards that have been replaned. But this tool is much easier to handle than a radiused sanding block when top profiling a saddle.

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Shown on page 17 of our latest catalog.