top of page
Fretboard radius Sanding Tools | GMC Luthier Tools


GMC Luthier Tools Fretboard Radius Sanding Tool is capable of sanding any desired radius between 7.25” and 20”.

The kit is supplied with 5 interchangeable tool plates for 7.25", 9.5", 12", 15" & 20" radius.


In addition to the specified sizes, the close spacing of the tool plates - see photo of plates stacked - also allows the kit to create any radius between the range of 7.25” and 20”. 


To sand a fretboard radius that doesn't correspond to a plate, the next size tool should be selected. The desired radius is achieved by alternating the pressure at each the side of the fretboard and checking the progress with a gauge. A set of radius gauges is included.



  • Set of 5 Fretboard Radius Sanding Plates: 7.25", 9.5", 12", 15", & 20".

  • Hardwood Handle.

  • 5 x Ø150mm PSA Sanding Discs 80 Grit.

  • 5 x Ø150mm PSA Sanding Discs 120 Grit.

  • Set of 3 Radius Gauges.



Replacement abrasive is also available from the webstore.



The short length of the tool provides a good sanding rate with 2-handed use.


The system utilises standard PSA (Pressure Sensitive Adhesive) abrasive discs and is also suitable for 2-3/4" stikit roll. The abrasive supplied is suitable for rough shaping and semi-finishing the fretboard. (Fine grit abrasive for finishing the board can be used with the tool but is not included).


The tool plates are 75mm wide x 150mm long with rounded ends to match the abrasive discs. The extra abrasive at the sides of the tool can be trimmed off or utilised by rotating the abrasive around when worn.


The tool plates can also be used without the handle when less pressure or a reduced sanding rate is required. This is useful when finishing the fretboard using fine abrasives that are not PSA backed. The tool plates are comfortable to use in this manner and the abrasive can be folded around and gripped at the sides of the plate.


Q. “How can I achieve a specific radius when there isn't a specific tool?”

A. Use the next size up and check progress with the radius gauges. Apply a little more pressure at the sides when semi-finishing to get the radius required.


(Please Note. The neck support jig shown in the illustrations is not included. For reference, the jig is based on our standard fret slotting jig base fitted with the 1-piece neck adaptation).

Guitar making tools - Fretboard radius sanding tool
Guitar making tools - Fretboard sanding
Guitar making tools UK - Fretboard Sanding Tool Sizes
Guitar making tools - Fretboard sanding box

The one-piece neck adaptation fitted to the slotting jig base provides an excellent setup for sanding the fretboard radius.

The finished guitar can be viewed here.

Guitar making tools UK - Fretboard Sanding Jig
bottom of page