We offer a number of options regarding how holes are drilled in the headstock for tuners.

Hole Style Size Example Tuners that will fit
None (headstock will be undrilled) N/A N/A
Vintage 8.7mm / .345″ Fender Vintage Style Tuners, Kluson Vintage, Gotoh SXB510
Modern 10mm / .394″ Almost every modern tuner, including Gotoh SG381, Fender Modern Tuners.

7.8mm + 9.8mm

.307″ + .390″

Gotoh, Grover and Schaller sealed tuners.

Why bother with this counterbore? The sealed tuner’s housing is a larger diameter than the threaded bushing. Under string tension, the bushing (and the peghead washer) can lean slightly in a single diameter tuner hole. This can damage the finish around the bushing and possibly cause tuning issues. A properly sized tuner hole prevents the problem.

Please measure your tuners to be sure of your measurements! There have been many variations over the years. Tuner holes can be redrilled or reamed larger… but it is hard to do this keeping both sides of the holes clean. And we haven’t figured out how to make the holes smaller.

If you have a unique or unusual tuner hole size need, please contact us.