Proper Nut Slot Height

Dave Johnson is the founder of Scale Model Guitars and a Guitar Craft Academy faculty member.

Large T Slot Nuts

(1) String height above the fingerboard at the nut (a normal fret is.035') (1) String height above the first fret (2) String height above the 5th fret, no relief (3) String height above the 5th fret with relief (4) String height above the 12th fret with no relief (5) String height above the 12th fret with relief. Acoustic Guitar Setup Tips and Ideas. The Trifecta of Guitar Setup. I always do setups in this order: 1) relief, 2) nut, 3) saddle because a) relief can affect the other two and b) there is essentially one correct nut height and it will affect the overall action. For nut slot repair, use the sharp tip to “prime” the bottom of the nut slot by pushing it into the slot at three or four points along it’s width. This helps the new material grip the bottom of the nut slot and resist breaking free prematurely. Put a tiny drop of Krazy Glue in the freshly cleaned slot, careful not to let it run. This procedure is for lowering string height on the first fret of an acoustic guitar. I filed the nut slots to make them lower. Here is the link to the tool. In my mind, the nut slots need to come down, and the shim needs to come out. When that is correct, I can raise the bridge saddles to compensate for lower string height. When I fret it at the 4th fret, and measure the gap from the first fret to the bottom of the string, a.010 feeler gauge has plenty of room to flop around in there.

Proper Nut Slot Height Chart

For this month’s tech tip, I will show you a quick way to fill and recut a nut slot in order to raise it up.

A slot that is cut correctly should hold the string in place at a height that clears the first fret. Sometimes a guitar nut slot will wear down over time and cause the string to rattle against the first fret, causing the open string to sound a little more like a sitar than a guitar.

Proper Nut Slot Height Bars

There are several ways to repair this issue. You can use dust or baking soda with glue, but I’ve found that a Q-Tip works very well too. You simply tape off the ends of the nut and then remove a small portion of the cloth and roll it up, then insert it into the slot that is too low. Then flow a thin super glue into the fibers using a thin whip tip. You can find thin super glue with whip tips on stewmac.com (the part number is #0010).

You can either drop super glue accelerator on the soaked Q-Tip or wait a few minutes for it to harden. Once it is cured and solid, you will then flush cut the ends of the hard fibers with a razor blade and then recut the nut slot to the appropriate height with a gauged nut file. This process would be included in any guitar setup and it’s a handy skill to have to ensure that your guitar plays and sounds great!

Proper Nut Slot Height Dimensions

– Dave Johnson