Neck Relief — Lutherie Encyclopedia

Neck ReliefType: glossaryA slight concave bow in the neck that provides clearance for string vibration, adjusted via the truss rod.## Definition Neck relief is the slight concave curvature (forward bow) intentionally set into a guitar neck to accommodate the elliptical vibration pattern of a plucked string. When a string vibrates, it moves in a wide arc near its center and a narrow arc near its endpoints. A perfectly straight neck would cause the string to buzz against the middle frets even with adequate action at the nut and saddle. A small amount of relief, typically between 0.15mm and 0.40mm measured at the midpoint of the neck, provides the necessary clearance. Relief is distinct from action, though the two are closely related. Action is the absolute string height at a given fret, while relief describes the curvature of the neck itself. Adjusting relief changes the action in the middle frets more than at the endpoints. ## In Practice Neck relief is measured by fretting a string at the first fret and at the fret where the neck meets the body (usually the 14th fret), then checking the gap between the string and the frets in the middle of the neck, typically at the 7th or 8th fret. This gap is the relief measurement. Relief is adjusted using the truss rod: tightening the rod reduces relief (straightens or back-bows the neck), while loosening it increases relief (allows the neck to bow forward under string tension). A luthier adjusts relief as part of a complete setup, typically setting it before adjusting action at the saddle and nut. The ideal amount of relief depends on playing style, string gauge, a…