Crowning file
A shaped abrasive file, usually with a concave or curved face, used to restore the rounded profile of a fret's top after levelling.
Levelling flattens the crowns of the frets into small flats, which would produce a dull, imprecise note if left alone. Crowning puts the round profile back so the string contacts a single narrow point, and it is done with files ground to a radius that matches the intended crown and sometimes dressed with progressively finer grits. The work is delicate: over-crown a fret and it becomes too low and starts buzzing.
Example: after levelling a board with high frets, a crowning file and then a polish are what make the notes clean instead of thin and buzzy.
See also
Related
- PageFret level
- PageRe-crown
- PageAction gauge
- PageAged finish
- PageBack bow
- PageAaron Dessner
- PageAce Frehley
- PageAd-Rock