8" Radius Blocks

  • 122 Reviews
  • Write a review

Accurately true or change a fingerboard's radius and level frets.
We make these hardwood blocks for use with Stikit Abrasives, to radius a fretboard quickly, accurately and without guesswork.

Read more

7-1/4" radius

Item # 0415
In stock, ready to ship!



9-1/2" radius

Item # 0405
In stock, ready to ship!



10" radius

Item # 0416
In stock, ready to ship!



11" radius

Item # 0406
In stock, ready to ship!



12" radius

Item # 0417
In stock, ready to ship!



14" radius

Item # 0419
In stock, ready to ship!



15" radius

Item # 0420
In stock, ready to ship!



16" radius

Item # 0418
In stock, ready to ship!



17" radius

Item # 0421
In stock, ready to ship!



20" radius

Item # 0403
In stock, ready to ship!


Total: $0.00
Quantity: 20

Product Details

Accurately true or change a fingerboard's radius and level frets.
We make these hardwood blocks for use with Stikit Abrasives, to radius a fretboard quickly, accurately and without guesswork.

Shaping fingerboards: use 80 through 220-grit
Leveling frets: use 220 through 400-grit

When working on compound radius fretboards, simply change blocks as you progress along the neck.

Dimensions: 8" (203.20mm) long x 2-3/4" (69.85mm) wide

See our shorter blocks for spot leveling, and for use as clamping cauls when gluing frets.

What's your radius?
Quickly find the curvature of a fingerboard or bridge with a set of radius gauges. Use them frequently to check your work as you smooth or shape a fingerboard or frets: a quick visual check keeps you from accidentally altering the shape—a mistake that's easy to make and hard to fix.

Radius Gauges

Product Instructions

Radius Block Basics

An explanation of the different uses of a radiused sanding block.

Ratings & Reviews

8" Radius Blocks

  • Based on 122 Reviews
Displaying 8 of 13 1 2 3 4 5 6 7 8 9 10 11 12 13
Write a review

Great purchase!

By Quicksilver44 from FL
(Customer's Reviews) Friday, December 30, 2011

I've got a Squier Fretless J-bass and I found that 1) the fretlines on the board were raised very slightly and you could feel them as you move your finger along the board and that, more importantly, 2) in pursuit of super low action on the bass (since it's a fretless), the string would die out and choke at the 7th fret position on the bass excessively, under almost all conditions (either with flat neck or a little bit to a lot of bow and low string height). So I bought this block and went over the fingerboard with 220, 320, 400, 600, 800 and 1000 grit sandpapers and these two issues had been eliminated! Plus the (ebonol) board looks really beautiful now! Very smooth feel and appearance. I thank StewMac very much for a great product and a great price!

Stew Mac's got your back.

By Bruce Kunkel from East Stroudsburg, PA
(Customer's Reviews) Wednesday, December 21, 2011

Received an 8"x 12R sanding block with a couple of small knots in the working face and was not happy about it but needed to use it. I sent an email to Stewmac and they sent me a perfect one and told me they didn't want the other one back. That's the way it's supposed to be! That's why I give them most of my business and have since the early '70's.


By drinkbarmits from Tokyo, JAPAN
(Customer's Reviews) Wednesday, December 07, 2011

Beautiful Flametop. This would be so cool to be painted by clear color. Good weight.

Does just what it's supposed to do, just how they say it will

By Rayzor from Lenawee county Michigan
(Customer's Reviews) Friday, November 18, 2011

I've built a few blocks myself and have never built one in less than 2 hrs. I needed a 12" for this last build and thew one in the last order, just to save the hassle. For fun I checked the radius against an L.S.Starrett radius gauge and found it to be spot on perfect. I then checked against my granite Rt angle surface plate and found the sides to run parallel with the radiused surface. This is a VERY well made block.


By Armen Movsesian from Moscow, Russia
(Customer's Reviews) Sunday, November 06, 2011

It is necessary to have to everyone!

Every luthier needs one

By praisegig from Texas
(Customer's Reviews) Wednesday, November 02, 2011

top notch material, easy to use


By drimmon from Russia
(Customer's Reviews) Thursday, October 27, 2011


Perfect for the task

By Geoffrey from Adelaide, Australia
(Customer's Reviews) Sunday, October 09, 2011

The Wooden Radius Sanding Blocks are ideal for flushing fretboard inlays and any final sanding on the fretboard. Worked a treat!

Sanding blocks

By Kenny Fox from Perth, Australia
(Customer's Reviews) Saturday, October 08, 2011

Simple and robust, should last for many years. I've even used mine to level the frets.

Machining Grooves

By Feral Customs from Seattle, WA
(Customer's Reviews) Sunday, October 02, 2011

The blocks I receive work just fine, but the radius of them aren't perfect. There are definite machining grooves on the radius left over from the shaping process. They're not large, and with human error taken into account during the sanding of a fingerboard they don't affect the final product a noticeable amount, but they're there none the less.

Displaying 8 of 13
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Shown on page 11 of our latest catalog.