How To Level, Crown, and Polish Guitar Frets

Leveling of guitar frets may need to be performed for several reasons:

  • To level newly installed frets
  • To correct inconsistent fret height that causes buzzing
  • To remove shallow grooves worn into the fret
  • To re-crown frets flattened by string bending
  • To lower frets that are too tall for a players preference
  • Filing Frets Level

Regardless of the reason a Level, Crown, and Polish job can be a daunting task to take on for the first-timer. Or at least it can seem that way.

Just like any other precision work you have to take it on with a bit of patience. Go slow, measure twice, and check the instruction guide at each step to ensure you don’t miss anything.

Follow my guide below and you’ll be sure to get the job done right. Most importantly, you’ll save yourself almost $200.

Tools you’re going to need:

  • Fretbar Leveler or Straightbar
  • Fretboard guard or masking tape
  • 320 and 400-grit sandpaper
  • 400, 600, 1200, 4000, and 6000-grits polishing paper
  • Micro-Mesh Foam Sanding Block
  • Set of or just the right crowning file

Step 1: Level the frets

After removing the strings, taping off between each fret to protect your fretboard, and covering your pickups attach a long strip of 320 grit sandpaper to the straightbar or fretbar.

It’s a good idea to remove your nut as well if possible. This will protect you from a costly mistake when you bump into it ripping up part of the fretboard.

passing file across frets from one end of neck to the other
A very long file is used to insure even fret removal and
consistent fret height.

When performing a fret leveling on a guitar the frets are filed as a whole, not individually. This insures that the crown of one fret is not lower or higher than the one next to it.

leveled frets with flattened crown

Before filing the frets the neck is adjusted flat, the fingerboard masked and the crowns inked with a Sharpie. This ink gives a visual indication to the progress being made and quickly uncovers high frets.

After leveling, the frets crown is not flat and must be re-crowned.

Step 2: Crowning

The crown of the fret is the center peak which contacts the strings when fretting.

The roundness of the fret makes it comfortable to play; the crown insures proper string length and intonation.

A special file, known as a Fret Crowning File has rounded, concave surfaces which round over the now flattened fret.

Frets are filed until a sliver of the crown’s peak remains, untouched. This ensures no height was removed by overzealous crowning.

crowned frets have rounded top
Crowning rounds the fret to ensure the string
makes contact at dead center.

Step 3: Polishing

Once the frets have been crowned we are left with level, albeit scratched fret wire. In order to achieve a polished, smooth finish the frets are lightly sanded and polished.

Starting with the 400 grit polishing paper wrap a piece around the Micro-Mesh Foam Sanding Block. Run the block over the frets starting at the first fret and ending at the bottom, then returning up to the headstock. Do this back and forth motion 2-4 times with each grit of polishing paper.

Some reasons why a Fret Level, Crown, and Polish may be necessary.

Changing Fret Height

Fret height is of course a big factor when considering fret leveling and there is a limit to how short a fret can be and still do its job, well. Very short frets (say under .025 tall) can create a buzzing problem for some players, especially when the fret width is narrow. The strings need to bend down and over the fret to produce a clear note. A very low fret often dictates the need for more pressure or applying pressure closer to the fret to obtain a clear note. Something that is difficult to adapt to.

Removing Deep Grooves

Grooves worn in the tops of frets can sometimes be removed. When considering this option the height of the crown is measured and the depth of the groove subtracted from its measurement. If the math says the remaining height is too short to play cleanly the frets must be replaced.

High / Low Frets

Before frets are ever filed they are checked to ensure they need it!! Unfortunately people can and do jump to conclusions about fret height and needlessly file the frets. Usually after hearing a buzz they are unable to identify.

While a high or low fret may be the culprit, it is far better to be certain than needlessly remove the playing life of the frets.

Common Symptoms

Let’s say you are playing an A note on the 5th fret and a noticeable buzz is heard, but, after moving up to the 6th fret the buzzing disappears. All other notes play cleanly but this one in particular is always buzzing.

The first thing to rule out is a loose fret that has sprung free from the fingerboard and now sits higher than its peers. Loose frets should be seated and the instrument re-evaluated. On occasion, re-seating a loose fret may not render the frets perfectly level. When that’s the case, a level and dress is in order.

On acoustic and hollow body guitars you may occasionally see a hump in the fingerboard where it joins the body. Sometimes this hump is caused by dryness. When a lack of humidity is the culprit the instrument should be given proper humidity to allow it to stabilize and then re-evaluate.

When unevenness of the fingerboard cannot be remedied with humidity one will either end up leveling the frets, or, in some of the worst cases, remove them to plane the fingerboard before re-fretting.

Once again, thank you for checking out Music Speaks Magazine’s Tech Support guides. We hope you found this one useful. If you have any questions or requests for how-to guides feel free to leave a comment or reach out to us via email at We’d love to hear from you!

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