Fret Crowning — Lutherie Encyclopedia

Fret CrowningType: techniqueReshaping fret tops from flat (after leveling) back to a rounded profile, ensuring precise string contact and clean intonation.## Overview Fret crowning is the process of reshaping fret tops after leveling. Fret leveling necessarily flattens the tops of the frets, creating a wide, flat contact area with the string. This flat surface causes intonation problems because the string's contact point becomes ambiguous—the note can change pitch depending on where on the flat the string actually touches. Crowning restores the rounded peak of each fret, creating a single, precise contact point that ensures accurate intonation and clean tone. ## Process Crowning is performed immediately after fret leveling, before the masking tape is removed. The luthier uses a crowning file—a specialized file with a concave cutting surface that matches the fret's profile—to remove material from both sides of each fret, leaving a narrow, rounded peak at the center. The file is run along the length of each fret, angled slightly to one side, then the other, symmetrically reducing the flat area created by leveling. The goal is to reduce the flat to a thin line (approximately 0.5-1.0mm wide), centered on the fret, with smoothly rounded shoulders. After crowning with the file, the frets are progressively smoothed using finer abrasives: 400-grit sandpaper, 600-grit, 800-grit, then 1000-1500 grit. Some luthiers continue to 2000 grit or use micro-mesh pads up to 12000 grit. The final step is polishing, which brings the frets to a mirror shine. This is done with fine steel wool (0000), polishing compound on a cloth, or a felt wheel on…