File to crown Medium size fretsfrom 2mm to 2.4mm (0.80" and 0.95"). Once the frets have been set and the ends have been beveled, we will proceed to level and crown them. To do this, we can use this file. The handle is covered in plastic and allows a firm grip. The abrasive surface is curved to shape the fret at the ends. It comes with a practical plastic case for hanging on a tool panel.