Fret — Lutherie Encyclopedia

FretType: glossaryA thin metal wire strip embedded across the fingerboard that defines precise pitch intervals when a string is pressed against it.## Definition A fret is a thin strip of metal wire, typically nickel-silver (an alloy of copper, zinc, and nickel) or stainless steel, set into slots cut across the fingerboard of a stringed instrument. When a player presses a string down behind a fret, the string contacts the fret crown, which becomes the new vibration termination point and shortens the speaking length of the string to produce a higher pitch. Frets are spaced according to the equal temperament tuning system, with each successive fret raising the pitch by one semitone. Fret wire comes in various profiles described by crown width and height. Wider, taller frets are often preferred for string bending, while narrower, lower frets give a smoother feel closer to a fretless instrument. Common sizes include medium (roughly 2.0mm wide by 1.0mm tall) and jumbo (2.7mm wide by 1.4mm tall). ## In Practice Installing frets, or fretting, is a precision operation. The fret tang is pressed or hammered into a pre-cut slot in the fingerboard, where small barbs on the tang grip the slot walls to hold the fret in place. After all frets are installed, the luthier levels them to a common plane, then re-crowns each fret to restore its rounded profile, and finally polishes them to a mirror finish. This leveling, crowning, and polishing process is critical for clean playability without buzz. Frets wear over time as strings dig grooves into the soft metal, eventually requiring a re-level or complete refret.