This is nuts… or at least it’s about nuts

19 Feb

Hey again,


If any of you'z get outta line...

I thought you may find this useful, assuming you’re up for squeezing every bit of performance out of your guitars.  Even better, it’s the kind of performance that costs little or nothing.

I’ve put some diagrams and links below for you. Don’t let the simplicity of these sketches – or the lack of whiz-bang graphics or Pixar quality animation fool you.  There’s some next-level ninja stuff going on here.  Even if you just follow the basic size and shape guidelines you’ll be ahead of the majority of guitar players and luthiers out there.

Also, there have been some great comments and questions on these, so I’ve included some thoughts and clarifications below the diagrams.

I’ve found that so much of a guitar’s performance is locked up in the finer details that are often overlooked. It’s all of these seemingly insignificant details working in together that add up to un-common, killer guitar performance.  Stick with me here and I’ll reveal some of my best-kept secrets below.  I’ll be divulging more of them in the near future.

So I have a good friend and client who has a pretty sweet collection of 30 (or is it 40…) guitars.  We’re not necessarily talking about anything that needs to be sealed in a glass case or surrounded by armed guards…  but some pretty high level, solid, pro-level guitars and a few choice – highly coveted models from the late 50’s and 60’s.

Over the years we’ve made it a point to regularly get a few of them on the bench and really… massage them into what they’re capable of becoming, with the goal being sooner or later we’d have gone through all of them.  Because the reality is, for many (if not most) of the guitars – the thought of playing them is better than actually playing them.  Most of them are in some state of “disappointing” or sub-awesome to play.

One of the challenges has been that I’m usually booked up 4-6 months, so if you do the math… we’re not going to get to very many of his guitars… any time soon.

Sweet 69 Les Paul Gold top

Every time we give one of his guitars some “love”…  when he gets it back in his hands, the difference is so significant that he just scratches his head… and grins while getting lost in the awesomeness and joy of playing his “new” guitar.   He’ll tell me, “now this one gets to live in the ‘I wanna play that’ section of my guitar collection”.  Quite a few times we’ve turned the “stinkers” of his collection into regular go-to guitars.

So recently he’s been hinting… nudging… heck, lately he’s been begging me to teach him some of the more key tricks that I use to bring each of his guitars to life.  He wants to be able to do more of this guitar work himself – so hopefully he can work his way through the collection within the not-too-distant future… at least sometime before he’s pushing up daisies.   And not just for time’s sake…  putting a guitar on my bench isn’t cheap.

So long story short, after much arm twisting… I finally gave in.  The first area we decided to go over was proper nut design.  And not just in basic, traditional terms of what’s been accepted (acceptable?) over the years…  but what is it specifically that I’m doing to make his guitars so (in his words) clear, full, rich, and powerful – with that extra “sparkle” as he called it.

So I proceeded to sketch him out some of the tricks and guidelines that I use for my nut design.  I just scanned them for you and (tried to) create a download link to them somewhere below.

You should be able to just click on the pictures (Right Click > Save As… to save).  Excuse my technologically-challenged-ness…  maybe someday I’ll figure out how to get stuff like this onto the site, like I actually know what I’m doing  🙂

I’ll work up a more in-depth nut tutorial sometime soon, but this should get you on the right track.

Nut slot design guidelines:

Secret Ninja nut slot bottom details:

A few questions and clarifications from readers and students:

Q: What does the slight “relief” v at the bottom of the rounded nut slot actually do?  Why is it needed?

A: Re your question about the relief v…  “needed” may be slightly strong, as a just a good fitting nut slot (without the relief) goes a long way.  The relief is just that “little bit extra” that keeps the string… planted and connected.

I find that ANY string movement at all in the nut (and on the saddle) can “color” the sound.  The obvious/extreme case being the “sitar-like” sound you’ve probably experienced by a string that wasn’t mated properly to a nut or saddle.

But on the more subtle level, the extra relief (which is very slight… down to a line scribed with a fresh X-Acto blade for a .024″ – .026″ string), will positively locate the string, help it to mate itself to the slot, and eliminate any chance of the string rattling in the slot.  I mean even rattling on a micro level.

To me any movement will make the sound… less pure.  I only want to hear the string, the wood and the nut and saddle material.  I want the sound as pure and rich and strong as possible, pre-electronics.

One day I’ll show you how I like to perfectly mate each string to its slot.

Q: Cutting the nuts sounds like such an exacting measurement the way you suggest. Where would one get the nut files to achieve both the round bottom and the exact fit?

A: It’s actually not so hard to do.  One tool that should be required for anyone who even talks about wanting to make their guitar play better is a digital caliper – one that measures in .001″ (one-thousandth of an inch) increments.

Why? You never want to assume a nut file OR a string is the size that it says.  Always measure.

As far as the nut files to do this, if you don’t have a set of them, you can actually use a combination of drill bits with 240 grit sandpaper wrapped around them (I prefer sticky-back), or even the drill bits themselves (though you can’t use too much bending pressure on the smaller ones), and even use thin feeler gauges/sandpaper in the same manner.

The best way (if you’re looking to do this on multiple guitars, do some work for others, or even make some money doing this) may be to get 1 good set of nut files, and fill in the odd sizes with the sandpaper technique.  I even wrap one edge of my nut files with sticky-back sandpaper for some exacting size options.

But understandably, that may not be in your budget, so…

Since the smallest files are the hardest  ones to “improvise” and get an accurate size and rounded bottom, you may want to at least grab a .010″ and .014″ – and a .017″ for extra credit (assuming you’re playing an electric with .010″-.046″strings). Basically go no more than .001″ above the string size. You can tune/enlarge the slots slightly with some fine sandpaper.

The key is to always measure.  Simply having slots that fit the strings and having good geometry will go a long way towards excellent guitar performance.


One thing I forgot to mention is that when I go the extra step and do this small “v” relief in the center of the slot, it’s usually reserved for the E, A, D and sometimes G strings… and I’ll just be sure that the rest are fitted/mated accurately with their respective slots.

Also, the v is… very small.  More is not better.  And be sure you don’t create any type of burr alongside the relief.

You may be concerned about the string binding in the nut slot, and the common assumption/solution is to make the slot bigger/sloppier than the string (and away goes tone, sustain and volume…).  Sure, this can help, but it’s common for me to see a string bind – usually a plain or very small wound one – even when the slot is significantly larger.

What’s overlooked is that the friction coefficient of the two materials together (usually bone and steel) are fairly high.  That high pitched “tink” you’ve undoubtedly heard on strings 1 – 3 when tuning up, is as much an issue of materials involved as it is slot size.

The friction coefficient can actually go up if the string’s load is only focused on a tiny spot, as in the small string/larger slot example. Visualize that a slot doesn’t have to be much (or any) larger for the strings contact point to become very narrow.

You may not buy the analogy, but I think of it like an auto engine main bearing:  The smoothest, lowest friction bearing is perfectly fitted to it’s “journal” (the guitar string in our example), with just enough space for a thin layer of lubricant.  This is also a combination that will last for hundreds of thousands of miles.

The opposite combination – bearing larger than the journal – will be rough, noisy, inefficient at transferring power, and it will wear quickly.  Are you seeing the similarities?

High level guitar performance doesn’t just happen by itself, and I generally reserve this finer technique/strategy for the clients who are willing to put at least a little effort into their setup and maintenance.

Given the significant compromise that’s accepted in the luthier/guitar tech/tinkerer world as far as how a string fits in the nut slot, here’s my final take:

When stuck with the choice of accepting a sloppy fitting string/nut slot, or going for the highest level solution… if it’s a higher level client, student, or my personal guitar, I’ll make the slot fit perfectly, and use a dot of lubricant in each slot.  I can hear the whining… “you expect me to add a dot of lube EVERY TIME I change strings?!…”

I even like to take it up a few notches higher.  Not just accepting the first thing in my medicine cabinet (i.e. Vaseline etc), I found some awesome stuff that fits the situation perfectly:

Dumonde Tech “Liquid Grease”.  Interesting stuff… Once regular grease is wiped away from a surface (say, by a moving string…) it doesn’t flow back to re-lubricate the area. This stuff has just the slightest bit of flow, but not enough to run.  And has insanely high film strength.  Good enough at 140 mph, good enough for a guitar I suppose. And cheap for the little bottle that will last you forever.

I have a longtime love (since childhood) of all things high-performance motorcycle.  I’ve even built engines for numerous national and world champions.  So it’s impossible for me to NOT draw extensively from this background when searching for more guitar performance – whereas the more common background for luthiers starts with being a musician and/or woodworker (yes, I have that too…)

Anyway, I hope this helps give your guitar some more mojo.   Let me know if you have any questions or need me to clarify anything.  Just post a reply in the comments section below and I’ll answer your question directly.
Talk to you soon,

Bernie / FretGuru


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