Fret Wear Scale
Fret wear is quantified using digital micrometer readings at crown height, benchmarked against original manufacturer specifications.
We measure crown height at 12 fret positions across the neck—three points per string—using a digital micrometer calibrated to 0.001 mm. These readings are compared against factory specs for the exact year and model, accounting for original fret wire dimensions and radius. This eliminates assumptions about wear severity based on age or appearance alone.
For example, a 1958 Les Paul Standard with original frets might show crown heights averaging 0.82 mm on the low E string at frets 5–7, while factory spec for that model year is 0.85 mm. A deviation of ≤0.08 mm across the playable zone typically indicates minimal playing wear rather than previous resawns. We document all measurement points and offsets in the full report.
Fret wear alone does not define grade unless combined with structural evidence—like fret ends protruding or neck relief altered beyond original specs. Our scale distinguishes cosmetic flattening from functional wear (e.g., G-string grooves deeper than others may point to playing handedness without damage). All readings are stored in the guitar’s digital traceability file.
