1. Gibson Nut Slot Height Dimensions
2. Gibson Nut Slot Height Chart
3. Gibson Nut Slot Height Bars
4. Gibson Nut Slot Height Weight Chart

Here's a gnat's-eye view at the face of a nut as seen from the leeward side of the second fret. The slots for these two strings are cut so that they completely support the string.

Steps to Get the Nut Height Filed Correctly. In order to make adjustments to the action of the nut, you will need a set of files, one that coincides with the width of each string rut in the nut, a feeler gauge, a tuner, and some time and a whole lot of patience. The first thing you want to do is take your feeler gauge and check the distance. Ideally, the nut slot height is identical to any other fret. But remember that strings can 'saw' themselves through a nut just through normal use. I ordinarily leave a nut slot a little higher than necessary at first, to allow for the string to cut itself a little lower. String Height At The Nut. String height at the nut should be as low as possible without causing open string buzz. The distance between the string and the 1st fret would nearly always be below.020 (.5 mm). When I am certain of the condition of the frets I set action at the nut as low as possible.

The sketch above relates to fretted instruments, but the basic principles are no different for violin family and other unfretted instruments. I'll try to explain the clearance in a minute.

Here's an idea of how it works on a bass:

Having the slot cut too high above the frets (or an unfretted board of some type) means that the act of pressing the string down to the first few frets actually stretches the string, raising the pitch and throwing the intonation off in the process. Ideally, the nut slot height is identical to any other fret. But remember that strings can 'saw' themselves through a nut just through normal use. I ordinarily leave a nut slot a little higher than necessary at first, to allow for the string to cut itself a little lower. I also avoid synthetic and elephant ivory, both of which are too soft and rubbery to make good nuts for steel strings.

Here's a shimmed-up mess of a nut that has all the problems:

These slots are all too deep, but the B is still so high it doesn't play in tune, so someone shoved a piece of ebony under it to try and correct the intonation. Big 'Ugh' for this one.

People often comment on certain strings (e.g., mandolin A strings, guitar G strings) being more troublesome, always seeming to go out of tune during play. Mandolin A's are always the most troublesome because they have to make compound bends from the nut: back as well as to one side. And the length from the nut to the post being the other important factor. And being plain strings, they tend to bind if the slots aren't cut right. (The D's, being wound, tend to refine their own slots.)

When you tune, you always tune up to a note, never down, right? Right.

It's about friction in the slot.

And with a poorly cut nut, when you tune up, the tension on the length of string between the nut and the string post is greater (per unit of length) than the part you actually play, that's between the nut and the bridge. After getting the pitch just right, a bit of actual playing works the string, making the tension on both sides of the nut equalize, and voilà: you're out of tune in mid-phrase. It has nothing to do with the tuning machines, which people just love to blame, but everything to do with setup, particularly how precisely the string slots at the nut are cut.

A quick word about creaking guitar G strings: this issue is fading as elephant ivory nuts are fading. Bone is superior to ivory for a nut material because it's harder and burnishes better. Ivory is soft and actually registers the imprint of string windings. That irritating creak is the sound of the windings skidding over grooves impressed inside the nut slot. Once again: setup is everything. (You can resurface string slots in an ivory nut by inlaying bits of with pearl or bone, if you like.)

The string is a superb straightedge when it's under tension. This assumes the frets are really true and level.

The sketch below illustrates how - and how not - to shape a slot for any string.

Left: like the messy nut above, the nut material is too high. You need only enough to support half the diameter of the string. Anything more is just in the way. When the string is way below the top of the nut, you have great difficulty telling whether it's seating properly.

Next: a slot that's cut with a saw has a roughly flat bottom and also affords poor acoustic coupling. Saws seldom match the precise width of the string, which can roll side to side in the slot.

Next: strings will work their way down a v-cut, often bottoming out on frets (or the board, as the case may be with fretless instruments). The signal transfer is compromised because of the limited contact, and the string sizzles on the fret or the board. They also tend to bind and squeak. They can ruin your day.

Right: the slot really fits the diameter of the string, the nut material does not go above the halfway point of that diameter, and leaves the string a trace of clearance above the fret or the unfretted board surface.

Before going further, here's how to correct a string slot that's too low. Often it's wiser to repair a blown slot than it is to replace the whole nut.

Quick fixes like some kind of dust (bone, acrylic, baking soda) with superglue are really temporary. It takes little more effort to implant a little patch of bone (or even pearl) into the nut and recut the slot. It's as good as the original, and if done well, is quite invisible.

I have a couple of saws I use for widening and deepening in preparation for an implant. One is a fine hacksaw blade in a short handle, which is for wider strings. It leaves a nice flat-bottomed slot. The other is a backsaw such as one would use for cutting fret slots, which does the same and is good for finer strings. Avoiding hitting the first fret, assuming there is one, I cut down below the blown slot, sometimes almost to the board itself, angling the saw back a bit. Then I prepare the piece of bone (or whatever: ebony for a violin or cello) by carefully filing a piece of the material with a fine flat file until it slips snugly into the slot. I usually use old saddle scraps for this. A drop of CA and a tap and it's in there:

Trim and dress the nut as if it was new and uncut, then cut the new slot.

The slot itself needs to be shaped in a way that it not only fits the diameter of each individual string, but also such that the string has firm contact with the nut at the very front of the slot. This defines the end of the vibrating string length, and if it's not right, intonation will be impaired at the very least, and you may well find your string sizzling like a sitar string.

I prefer to shape my slots in the shape of a horn's bell:

The point of this is to offer a smooth surface for the string to travel from the tuning machine to the critical point of final contact at the front of the slot, where it is held firmly to define the end of the vibrating string length.

Strings have to make a compound bend at the nut, and to make tuning easiest while ensuring complete firm contact at the front of the slot, this horn bell shape makes certain the string glides smoothly, no matter the angle of approach. Here's a treble side view:

The bell here is imaginary. The nut is in yellow, the fingerboard is dark brown. The string is the green line, and the tuning machines are off to the right somewhere. Notice that the string connects with a smooth curved surface, no corner or edge. Whether the string is coming from the top or the bottom of the string post, it will slide smoothly into the nut slot. The string is in complete contact with the front 30% of the nut. There's plenty of substance there to keep the string from sawing its way deeper into the bone.

Here's the same slot seen looking straight down from above:

The string's other curve, from, say, the farthest peg on the bass side of the headstock, also elides with the inside of the bell-shaped slot, guided gently and directly to the front where it's held firmly by its own tension inside the confines of a well cut slot.

If the slot isn't properly angled back, several problems can arise.

If it's too flat (some repair books actually advocate this!) the string soon wears away the front of the slot and the functional point of contact is as much a 40% of the width of the nut back from the front edge, which can cause the note to ring poorly (because it's vibrating along a surface, not held to a point) and perhaps cause intonation problems. This is bad:

If the slot is angled back, but left a straight line, it will bind on the back edge, and the front edge will wear down from playing and the string is at risk for sizzling on the first fret or on the surface of the board. This is also bad:

The precise shape of the slot at the front edge is extremely important for sound quality, stability of the setup, and intonation.

More on bridges in due time, but the principles here apply to bridge slots on the viol and violin families, guitars, mandolins, and so on.
Here's a page on the files and so on you need to cut nuts.

Back to the repair index page.

Hello! Today we are going to go through the process of setting up a Les Paul style guitar with a tune-o-matic bridge and tailpiece. We will cover all the steps needed to make your guitar play better than it ever did from the factory and some tips and tricks along the way.

Evaluation

The first step in any setting up of an instrument is the initial evaluation. You want to go through the guitar and find out as many problems you are going to face here at this point so you don’t get halfway through the setup only to discover you overlooked something and have to waste time going back to correct it and repeat all of the steps over again.

Electronics

This is the best time to plug in the instrument and check out all of your pots, pickups, jack, and switches to make sure everything is working properly. This will allow you to take care of any electronic issues now that will save you time in the long run.

For example, a lot of grounding issues arise with guitars with a tune-o-matic bridge. The “string” ground (yellow arrow in the picture above) usually runs from the treble side post of the bridge or tailpiece and into the electronics cavity where it will be soldered to ground on the back of one of the potentiometers. These wires lose contact or become loose quite often. So, checking this now and correcting it is going to save your butt instead of you having to pull off your strings and bridge to pry out a bridge post or ferrule to replace the ground wire 3/4ths of the way through your setup.

Neck Relief

At this point, it is a good idea to straighten out the neck of your guitar. Doing this will help flush out any fret or nut issues that can be taken care of now before the new strings are put on and the setup started.

To straighten the neck you want to check how much relief there is first. You can use a straight edge ruler that is long enough to lay across the top of most of the frets of the neck or a notched straight edge that rests against the fretboard. Lay the ruler down the middle of the neck.

If there is too much relief, there will be a gap between the bottom of the ruler and the frets or fretboard near the middle of the neck. You will then need to grab your truss rod tool and turn the truss rod nut clockwise until that gap is gone on the bottom edge of the ruler.

If the neck has a back bow, the ruler will rock back and forth at the ends because the neck is bowed up in the middle. You will want to adjust the truss rod nut counter-clockwise until the ruler is resting flat and even across the frets and/or fretboard. you want to make sure the ruler is not rocking back and forth anymore and there is no gap along the bottom edge of the ruler and the frets and/or fretboard.

If you don’t have a straight edge or notched ruler, you can use a capo, a .005″ feeler gauge, and your hands to check the relief of your neck. Place the capo at the first fret. Then with the thumb of your right hand, fret the low E string down around the 17th fret.

Take the .005″ feeler gauge with your left hand and slide it between the bottom of the E string and the top of the 7th fret. You want this much relief in the neck. Adjust the truss rod until the feeler gauge fits between the bottom of the string and the fret.

Frets

Now with the neck straight we can check if there are any fret issues before we continue the setup. It is important to take care of any frets issues now so we can make sure that we can setup up the guitar as best we can without any buzzing or dead spots on the neck.

We will use the fret rocker tool to check all the frets on the neck and make sure there are no high frets. You also want to make sure that none of the frets are loose and popping up out of the fret slots. If there are loose and uneven frets then make sure the loose ones are reseated and glued down. Then you will want to level the frets and crown them before moving on.

Nut

This is also the best time to check the string heights at the nut and see if the nut needs to be replaced or shimmed. I can’t tell you how many times we have gotten Les Pauls straight from the factory where the nut slots were cut soo low that multiple strings were resting on the first fret when the neck relief was adjusted straight. If there are issues like this at the nut or you prefer a different material, then now is the time to have it taken out to be either replaced or shimmed.

Extracting and making a nut for a Les Paul is an art and can be tricky. It is strongly recommended to have a skilled technician perform this if needed. We will go through the steps of replacing a nut on a guitar in a later article so be sure to watch out for that one in the near future.

Remove Old Strings and Clean Up

After the evaluation process is finished, and we didn’t run into any of the issues listed above, then we can continue by removing the old strings and giving the guitar a good initial cleanup.

It is a good idea to slacken the strings before you cut them off. This will help reduce any stress or potential damage to the headstock from the sudden loss of tension.

Also, the tension of the strings is what usually keeps the bridge and tailpiece secure to the body so be careful. I usually like to hold the strings with my left hand right above the pickups and cut the strings there. That way I can have both ends secure in my hand when I cut it and keep the strings from flying around causing damage. It also allows me to keep the bridge and tailpiece from popping off and causing dings or scratches to the top of the body.

Now with the old strings off and the bridge and tailpiece off to the side you want to clean up the guitar before we put the new strings on.

I like to polish up the frets and clean and oil the fretboard first. You can use 0000 steel wool or a 320 grit Klingspor pad to polish the frets and break up any dirt that might be on the fingerboard. Then a conditioning oil is applied and allowed to soak in for a couple of minutes before being wiped clean.

While the oil is soaking in you can take this time to clean up the body, back of the neck, and headstock with your preferred choice of cleaner and polish.

I also like to tighten up any loose screws or nuts at this point, especially on the tuning pegs which can cause tuning issues if they are not secure.

After everything is secure and cleaned up we can put the bridge and tailpiece back on and throw on the new strings!

But before we put on the new strings, there are two options involving the tailpiece that we need to discuss.

The first option is adjusting the tailpiece as far down as it can go and pass the strings through normally. It is said that this improves tone and sustain.

This usually can be done without any problems, but be aware that your strings might be prone to breaking at the saddle prematurely if there is too much string break behind the bridge and causing too much stress on the string at this point.

The second option is called “Top Wrapping”. This is where the string is fed in through the front of the tailpiece and wrapped up over it and then over the bridge to the tuners. This method is said to make the strings feel a little “slinkier” and more comfortable for the right hand due to less of a break angle over the saddles.

Everyone has different preferences and the argument for the difference in tone is negligible with both methods, so give both ways a try and see what works or feels best for you. You can also try adjusting the tailpiece all the way down and then top wrapping the strings to try and get the “best of both worlds.” But experiment a little and see what you like!

New Strings and Neck Adjustment

New Strings

Ok, now with the guitar all cleaned up we can restring it with a fresh set of strings.

When restringing you want to have only a couple of string winds around each post and start with one above the string as it passes through the string hole in the tuner. This will pinch the string and help keep it from slipping and causing tuning issues. For the unwound strings, you may want 3 to 4 wraps around the posts to make sure you have the correct string break behind the nut for them since they are smaller in diameter than the wound ones.

Less winds the better since the angle of the headstock is already at 17-degrees and the break angle of the string behind the nut is achieved with only a couple of winds on the tuning post. This will decrease string pressure in the nut and help with tuning stability.

Put on all the strings and tune up to pitch. Grab each string individually and pull it gently up and around in a small circular motion near the middle of the fretboard to “stretch” the string and make sure the wraps around the posts are tight and are not going to move or constrict later causing tuning issues. Then retune the string to pitch. Do this a couple times for each string.

Adjust Neck

With the new strings on and stretched we can adjust the neck. We did this step already in the evaluation phase so most of the time the neck is already straight and ready to go, but if not, repeat the process we went through above until the neck is straight and there is a .005″ gap of relief between the bottom of the E strings and the top of the 7th fret.

Most guitar necks have a little bit of normal “warping” to them. One side more often than not has a little more bow than the other. So when adjusting the neck, you want to check the relief on both the low E and high E. Most times you will find that the Low E side has more relief than the high E side of the neck. This is usually ok unless the high E string is resting on top of the frets. Then you will need to add a little more relief to the neck until the high E has clearance over the frets. This is going to cause a larger relief gap on the low E side of the neck, but you’ve got to compromise a bit to ensure that the instrument is going to be set up as well as it can be.

If your neck is considerably warped, then we definitely recommend taking it in to get professionally evaluated to see if a more drastic repair is needed.

String Action

With the neck straight we can adjust the height of the strings which is called the string action.

Adjusting Bridge

Adjusting the string action on a Les Paul style guitar is pretty simple. The bridge sits on top of 2 thumbwheels which are threaded on to a post or into a ferrule installed on the top of the body. You rotate one of the thumbwheels clockwise to lower that side of the bridge or counter-clockwise to raise it. Some posts have a slot in the top of them where a flat head screwdriver can be used to easily adjust the bridge up or down.

You can use your fingers on the thumbwheels to adjust the action most of the time or pliers with some tape wrapped around the tips so you don’t eat up the metal plating on the thumbwheels. The adjustment is easiest if you detune the strings a little to reduce the string tension pushing down on the bridge.

But the best tool to use is the ESP multi spanner tool. It is a double-sided steel wrench where opposite sides of each end is toothed in order to turn the thumbwheels to lower or raise the action of a tune-o-matic bridge or tighten and loosen nuts. This tool is a must-have and saves you from tearing up the skin on your hands or slipping with the pliers and scratching up your guitar when trying to adjust the action.

Using a ruler or a string action gauge card and holding the guitar in playing position, measure from the top of the 12th fret to the bottom of the string. This is how you get the string action measurement. A good place to start for the action of a Les Paul is 4/64″ on the low E string and 3/64″ on the high E.

Depending on the guitar and playing style, the action can be adjusted slightly lower or higher from this starting point.

Bridge Saddle Radius

The bridge saddle radius should match or be slightly flatter than the radius of the fretboard. Most Les Paul fingerboards range between a 10″ and a 12″ radius. Using radius gauges, measure the fingerboard radius and the saddle radius and see if they match.

If the radius of both don’t match or they do and you want to flatten the radius a little, you can take the same files used to cut nut slots to cut the string notches in the saddles a little deeper in order to achieve the intended radius. When cutting the saddles, make sure to cut at a slightly downward angle towards the tailpiece to insure the string sits properly in the notch.

One common problem you will find is that the factory bridges will start to collapse or bow in the middle due to the soft metal they are made out of and tension of the strings pushing down on it over the years. So if you find the saddle radius to be extremely out of spec or you’ll cut into the intonation screw if you try to lower the string notch any further, then you will most likely need to replace the bridge on your guitar.

String Action at Nut

A critical adjustment that is easily overlooked is the string height at the nut. A correctly adjusted nut can help improve playability and intonation on the first couple of frets especially for barred or open chords.

Gibson Nut Slot Height Dimensions

To measure the height of the strings at the nut, we measure from the top of the first fret to the bottom of the string with our ruler. We then will use the proper nut files for the string gauges used to cut each slot in the nut to the desired depth. It is best to start slow and a little higher to make sure you don’t go too deep and cause the string to buzz on top of the first fret when played open.

It is also important to cut the nut slot in a slight downward angle. If the nut slot is flat, then the string will rattle and buzz when played open.

Another trick is to slightly cut the backside of the slots at an angle for the D and G strings towards their respective tuner posts. This will help alleviate any more friction of the string inside the slot which will help increase tuning stability.

A good place to start is at the factory heights which are 2/64″ for the Low E and A, 1.5/64″ for the D and G, and 1/64″ for the B and high E strings.

From here you can lower each slot until you feel each string is low and comfortable enough for your playing style. I wouldn’t go any lower than just above the 1/64″ mark for all the strings except the B and high E strings. These two strings can go down slightly further and still play and ring out normally.

After each slot is cut to the desired height, clean up any dust or debris from the area and apply a nut sauce or lubricant to each of them to help keep the strings moving freely and prevent any binding in the nut.

If you accidentally make one or more slots too low, then shimming the bottom of the nut or building up the nut slot will be needed in order to correct this.

Intonation

The final major adjustment is setting the intonation for each string.

Each saddle in the bridge is threaded on to a screw that can move the saddle forwards or backwards to adjust the length of the string in order to set the intonation correctly for each one. This will make the notes below and above the 12th fret as in tune as they can be with each other.

Using a strobe tuner is recommended, but most will do the job.

First, start by hitting the string open. Lets say the low E for example and tune it to pitch.

Then fret the low E string at the 12th fret and play the note. If the saddle is in the correct position, the notes should be the same pitch.

If the fretted note is higher or sharper than the open note then the saddle needs to be moved back. Use a small screwdriver to adjust the saddle. Retune the open note and check the fretted note again. Adjust until the 2 notes are the same.

If the fretted note is lower or flatter, then the saddle needs to move forward. Adjust the saddle and repeat the steps above until the notes are the same.

Repeat for all the strings until each strings saddle is in the correct position and proper intonation point.

Most of the time the saddle is easily adjustable with the note tuned up to pitch. On some bridges, the strings may need to be detuned a little in order to easily adjust the saddle forwards and backwards.

Sometimes a saddle will be adjusted as far forward or backwards as it can be and the intonation will still be off. Each saddle can be taken out of the bridge, the screw taken out, and then flipped around and reinstalled in the bridge in order to squeeze out a little more room for adjustment.

Gibson Nut Slot Height Chart

To do this, you want to slacken the string and move it over to the side of the saddle. Then you can take some needle nose pliers and remove one side of the retaining wire that helps keep the saddles in the bridge. Now you can remove the saddle, take the screw out, flip the saddle around, put the screw in the flipped side, and reinstall the saddle into the bridge.

Position the retaining wire back into place and over all of the intonation screws for the saddles like it was before. Place the string back on to the saddle, tune it to pitch and adjust the intonation.

After the intonation is set, apply some of that nut sauce or lubricant to each strings notch in the saddle to help reduce friction at this contact point for better tuning stability.

Pickup Height Adjustment

Pickup height adjustment is usually a pretty simple task on a Les Paul guitar. If your guitar has humbuckers or P-90 style pickups there is usually 2 height adjustment screws used to change the height of the pickup in relation to the strings to achieve the best tone.

For humbuckers , the screws are located on either side of the pickup on the pickup ring.

For P-90 or soapbar pickups, the adjustment screws are located on top of the pickup cover next to the pole pieces. There is usually foam or springs under the pickup to help keep it secure when it is raised up towards the strings. A lot of times there is not an adequate amount of foam or tall enough springs to raise the pickup up to the desired height and to keep it from flopping around and making noise. So, more foam or new springs (sometimes a combo of foam and springs) need to be installed under the pickup.

Some guitars have P-90’s or soap bar pickups that sit on and are secured to the top of the body with a special tab and pickup cover called a “dog-ear”. For these style pickups, a special shim is used which can be found online, in order to raise the pickup and cover up off of the body and look pleasing to the eye.

When adjusting your pickups, you want to make sure that the pickups are evenly matched volume wise. You want to do this through your amp with both volumes up and wide open. You also want to make sure that the notes ring loud and clear without any distortion or warbling which can happen if the pickup is too close to the strings.

The pickup height is measured by fretting the outer two E strings at the last fret and measuring from the top of the pole piece directly under that string to the bottom of the depressed string.

For the neck pickup, 6/64″ on the bass or Low E side and 5/64″ on the treble or high E side is the optimal place to start.

For the bridge pickup, 4/64″ on the bass side and 3.5/64″ on the treble side is usually best.

Gibson Nut Slot Height Bars

Every pickup, guitar, and ear is different so please use these measurements as a guideline and use your best judgement for adjusting the height of your pickups for achieving the best tone possible.

Final Polish and Cleanup

And that about wraps things up!

Gibson Nut Slot Height Weight Chart

Make sure all the truss rod and cavity covers are on and securely screwed back in to place, give your guitar a final wipe down, and go enjoy shredding on your newly fine-tuned axe!!!!