Practice

Mandolin nut

The nut sets the string spacing and open-string height at the headstock end. On a mandolin with 8 strings in 4 courses, the nut has 8 slots grouped in pairs. Slot spacing, depth, and width are critical — too tight and paired strings buzz against each other; too wide and the overall string spread exceeds the fretboard width.

Material affects open-string tone and sustain. Slot geometry must accommodate paired courses without binding or buzzing. Nut width determines overall string spread and playability.

Nut materials

Material Tone Durability Notes
Bone Bright, sustaining Excellent Traditional, self-lubricating to some degree. Requires hand-fitting. The standard on quality mandolins.
Synthetic (Tusq, Micarta, Corian) Slightly mellower than bone Excellent Consistent, easy to manufacture. Graph Tech Tusq is popular as a bone alternative.
Ebony Warm Moderate (wears faster) Occasionally used, especially on vintage instruments. Relatively soft compared to bone or synthetics.
Brass Bright, metallic Very good Uncommon on mandolins but occasionally seen. Sustain-enhancing. Can add a metallic quality to open strings.

Function

The nut sets the string spacing and open-string height at the headstock end. On a mandolin with 8 strings in 4 courses, the nut has 8 slots grouped in pairs. Slot spacing, depth, and width are critical — too tight and paired strings buzz against each other; too wide and the overall string spread exceeds the fretboard width.

Slot geometry

Each course slot must accommodate two strings sitting side by side. The geometry is more demanding than on a single-string instrument.

  • Width: the slot width is typically 0.04″–0.06″ wider than the combined string pair diameter. Enough room for both strings to vibrate freely without touching each other or the slot walls.
  • Angle: slots angled slightly toward the tuner post for smooth string travel. This prevents binding when tuning.
  • Depth: strings should sit about half their diameter above the nut surface. Too deep and they buzz on the first fret; too shallow and the action is unnecessarily high at the nut end.

Nut width

Standard mandolin nut width is approximately 1.1″ to 1.18″ (28–30mm). This is quite narrow — wider nuts spread courses further apart for easier fingerpicking; narrower nuts favor fast chord shapes.

  • Narrower (28mm): tighter course spacing. Fast chord changes, comfortable for smaller hands. Courses sit closer together, making fingerpicking more demanding.
  • Standard (29mm): the most common measurement on production mandolins. A balance between chord comfort and individual course access.
  • Wider (30mm+): more room between courses. Favored by fingerpickers and classical mandolinists. Chord stretches become slightly larger.

Compensation

Some builders angle or shape the nut for intonation compensation at the headstock end (zero fret, compensated nut). This addresses the pitch sharpening caused by pressing strings to the first fret. On mandolins, where courses must intonate together, nut compensation can make a meaningful difference in first-position tuning accuracy.