Correct Nut Slot Height
Specs for my stock nut height are.012 on the b - e.016 on the d - g and.020 on the e - a String fretted at the 2nd fret. Once you are sed to what it looks like you can do it by eye and feel. You must log in or register to reply here. Adjusting nut height An after-market bone nut, cut for our Balanced Light (10-48) Electric strings. The factors that cause action to shift over time (wear and tear, saddle height shifting, expansion and contraction of wood) tend not to have as substantial of effects on the nut than they do on the bridge or neck. 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.
Correct Nut Slot Height Chart
- Hello, my new Martin has high string height over the first fret. I have the tools and skills to cut the nut slots deeper. Although I have not been able to get a spec on what they should be at. Most of guitars are close to.4mm string hieght at the first fret.
- From the side you can see how shallow the nut slots are at this stage and how high off the frets the strings are. This is the basic method of setting nut slot height. Hold the string between the 2nd and 3rd fret and adjust the nut slot that each string just barely clears the 1st fret.
After adjusting the truss rod and setting the string saddle heights at the bridge, you can now make the third adjustment, which is to the nut slots. There are three aspects of the nut slots that you will be addressing in the setup process in order to make sure that they are cut correctly:
- The nut slot depths,
- The slot widths, and
- The slot angles.
When to adjust the nut slots
You typically make adjustments to the nut after setting the bridge, as the heights of the nut slots are a function of the overall string angle. The string angle is determined by the string action height at the bridge. The individual slot depths are cut so each string can clear the first fret.
You might notice that some guitars fresh off of the showroom floor are a little difficult to play in the first position (at the first five frets). This is because the manufacturer will cut the nut slots on the high side on purpose. Then a local guitar tech at the store can adjust them to customer taste. It is much easier to cut a nut slot down than to raise it by either filling the slots or shimming the entire nut up.
The effect of nut slots that are too high
Nut slots that are too high create a situation where the guitar is difficult to play in first position. They can also throw off the tuning and intonation. Nut slots that are too low will create what many players refer to as a “sitar” effect. This is where the string isn’t able to clear the first fret and rattles against it, creating a string buzz similar to a sitar.
The ideal nut slot height, in terms of playability, is subjective — much like string action height at the bridge. Some players like the slots to be cut up a little higher (like slide players), and some players want them cut down as low as possible so the guitar plays very easy with no fight.
You can measure the nut slot heights by placing a feeler gauge in between the bottom of the string and the top of the first fret when the guitar is up to pitch and after the neck and bridge are adjusted. This is why you use a capo at the first fret in all previous steps — to take the nut slot heights out of the equation, saving them for last.
Measuring the nut slot heights
You can start this process by making sure the guitar is up to pitch. Then read the nut slot depths. As a starting point, shoot for .02” in between the top of the first fret and the bottom of the string at the first fret on the wound strings (low E, A and D), and .018” for the plain strings (high G, B, and E). On acoustic guitars with a wound G, you will also shoot for .018” of space since this a thinner-wound string. The feeler gauge should be placed on top of the first fret, sliding underneath each string.
If there is extra space, then the slot is cut too high and will need to come down until the string lightly touches the top of the gauge. If the gauge pushes the string up, then the slot will need to be filled and re-cut to raise the slot.
Raising the nut slots
You can fill and re-cut a nut slot by wicking either bone dust or the rolled-up fibers of a Q-tip in the slot with thin Cyanoacrylate glue. Using a super glue accelerator to instantly toughen the material, trim the excess, and then re-cut the slot.
Widening the nut slots
The individual slot widths will be a function of the individual string gauges and will determine what gauged file you use on each nut slot. As a rule, you typically want to cut a nut slot slightly wider than the actual string so the slot does not bind or choke the strings at the nut. This can cause tuning issues.
Sometimes I will get a guitar in the shop to repair or replace tuners because the string is making a “clicking” sound when tuning. The customer assumes that the tuners are not working properly. However, most of the time the slots were binding the strings and hanging them up at the nut. I can fix the issue by simply widening the nut slots .002” over the size of the actual string width and cutting the slots correctly.
If, for instance, you are changing your string gauges from 10’s to 11’s, you will also want to widen the slots to accommodate the thicker string gauges. Again, these nut slot height measurements are workable specs to shoot for. But the customer will ultimately decide what feels right, as they can dramatically affect the playability of the setup.
Cutting at the proper angle
The last aspect of nut slot adjustment is the angle at which it’s cut. This is determined by the string pull of the headstock (either straight string pull or angled). Whenever you are cutting a nut slot, you will always direct the file in the slot to the corresponding tuning key.
Slot Nuts Sign In
On a Gibson, (which has symmetrical offset tuners) you will direct the file with a slight angle pointing to each tuner post. Gibson and Martin guitars have a tilt-back headstock design, so you will want to angle each nut slot cut with a slight downward angle that matches the headstock pitch, leaving the highest point of the slot at the front of the nut.
On Fender guitars with straight string pull, you’ll cut straight and in-line with the tuners. On Fender guitars with a scooped headstock design, you will want almost no angle in your cuts because there is almost no break angle in the string after it leaves the nut slot on the way to its corresponding post. If you cut a nut slot on a Fender guitar with an angle, you might create a string buzz on the open notes. You can almost always fix this issue by filling the nut slots and then re-cutting them correctly.
Dave Johnson is the founder of Scale Model Guitars and a Guitar Craft Academy faculty member.
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.
Correct Nut Slot Height Dimensions
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!
T Slot Nuts Sizes
– Dave Johnson