Detail 01
10 mm required peg holes
Confirm the guitar’s peg-hole diameter before installation.
Product detailSKU #1500000398485
Graph TechRatio 3+3 Acoustic Guitar Tuning Machine Heads Black 6 String
Independent shopping perspective
The Korena take
Designed for right-handed acoustic guitars with three tuners on each side of the headstock, this six-machine black Ratio set calibrates its gearing string by string. A 180-degree turn moves each string by a semitone, so tuning adjustments respond consistently across the set. The two-pin housings can mount directly, while the included InvisoMatch plates provide mounting options that use existing screw holes on most guitars.
Strong match
Who this is for
- Replacing tuners on a right-handed six-string acoustic with a 3-per-side headstock layout.
Consider the trade-offs
When to look elsewhere
- Six-in-line headstocks or left-handed guitar tuner layouts.
What matters in use
The specifications, translated
Catalog numbers tell only part of the story. These are the details most likely to change how this product feels, sounds, or fits into a setup.
Detail 02
Gear ratios: 39:1, 24:1, 20:1, 14:1, 20:1, 12:1
Each machine head uses its own calibrated ratio within the six-string set.
Final check
Know before you order
- 01Check for a right-handed, 3-per-side acoustic headstock and 10 mm peg holes.
- 02Four brushed-aluminum InvisoMatch mounting-plate sets are included.
Product questions
Before you decide
Straight answers to the questions shoppers most often ask about this product.
01How much pitch change does a half-turn make?
A half-turn corresponds to one semitone on each string.
02Can these use existing screw holes?
The included InvisoMatch mounting plates are intended to make use of existing screw mounting holes on most guitars.
Reference
Full specifications
The complete catalog record, organized around the decisions musicians make when comparing gear.
2 detailsPlayability
- String Post Diameter
- 0.236 inch (6mm)
- String Post Length to String Hole
- 0.910” (23mm)
1 detailsBody & build
- Color
- Black
1 detailsSize & weight
- Peg Holes Diameter Required
- 13/32 inch (10mm)
1 detailsOther
- Gear Ratio
- 39:1, 24:1, 20:1, 14:1, 20:1, 12:1
