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

A few minutes

By Kelly Jamison from Texas
(Customer's Reviews) Saturday, February 11, 2012

It took just a few minutes to set up the bridge with the understring radius gauges. I just needed to tweak a few things to adjust to my particular neck and I was playing in under 15 minutes. These gauges are a must for anyone seriously building guitars.

A necessary tool.

By Mario Bouchard from Quebec, PQ,Canada
(Customer's Reviews) Monday, February 06, 2012

I just got my Understring radius gauges and I made adjustments to a customerÆs guitar using them. I must admit that I never been able to do the job as fast accurately with without this tool. I really recommend the Understring radius gauges, itÆs a great tool! ThanksÆ to Stew Mac and their R&D department.

Understring Radius Gauges

By David Hinds from Australia
(Customer's Reviews) Monday, February 06, 2012

What a great product! Wish I'd gotten some ages ago! They just arrived and I immediately used them to set up my '62 Hot Rod Strat - 9.5" radius - feels and plays better than ever - brilliant!


By FT 150BL from france
(Customer's Reviews) Thursday, February 02, 2012

Very good and usefull tools. And not expensive at all. A very good idea.

great gauges

By will lee from savannah, ga
(Customer's Reviews) Tuesday, January 31, 2012

i bought the set to help me with setups...get them you wont regret it!!

Radius gauges

By Frank Bruce from Riverside,california.usa
(Customer's Reviews) Sunday, January 29, 2012

These are well made and accurate. Would recommend.

Makes Setups a Breeze

By M Dawes from South Shields, England
(Customer's Reviews) Sunday, January 22, 2012

I bought these Under String Radius Gauges as I thought they would minimise the amount of tools you need, as you can use them to set up your under string height, your pickup pole piece height and also to check the radius of the fret board, thatÆs exactly what they do. They are very high quality tools and are indispensable, as I have always set my string height using a precision rule by eye, but I was amazed when using these gauges to check out the string height on my guitars as I found they were all well out.

I have adjusted my favourite strat and the difference in the playability is remarkably more smoother and more comfortable, I will be using these gauges to set up all my guitars with confidence, I highly recommended these gauges as an essential tool.

Gauge yourself

By Frakin_sid from Nobama Land
(Customer's Reviews) Thursday, January 12, 2012

My string radius finally FEELS right. Do yourself a favor!

great little tool

By Ian Verner from Sydney, Australia
(Customer's Reviews) Sunday, January 01, 2012

I subscribe to the theory the optimum number of guitars is N+1, where N=the number you currently own. As such I have a wide range of radius's to deal with so this gauge is great to tune the latest purchase.

Essential Tool!

By Wilmer Gingerich from Jamesport MO
(Customer's Reviews) Saturday, December 17, 2011

Surely everybody has a set of these to go with the radius blocks? This is a no brainer.

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Shown on page 17 of our latest catalog.