Your guitar won’t stay in tune.
Someone tells you to install locking tuners.
Someone else says you need a locking nut.
And before long, a tuning problem that may have been caused by a badly cut $10 nut has turned into a hardware-shopping project.
Locking systems have real advantages. But they’re also credited with fixing problems that have very little to do with the tuners themselves.
Before replacing anything, it helps to understand what is actually happening to the string.
How Much String Is Really Wrapped Around a Tuner?
One common explanation for the supposed superiority of locking tuners is that conventional tuners leave several wraps of string around the post. Those wraps are said to stretch, move and make the guitar unstable.
Sounds reasonable.
But how much string are we talking about?
A typical guitar tuner post is about 6mm in diameter, or roughly 0.236 inch.
That gives us a circumference of:
0.236 × π = about 0.74 inch
With three complete wraps:
0.74 × 3 = about 2.2 inches of string
Now take a guitar with roughly a 25-inch scale length, another 2 inches of string behind the saddle, and perhaps 3 inches between the nut and tuner.
That’s about 30 inches of suspended string, plus roughly 2.2 inches wrapped around the tuner.
The tuner wraps make up only about 7% of the total string length.
Suddenly, those three wraps don’t look quite as terrifying.
Yes, Wrapped String Can Stretch — But That’s Not the Whole Story
Steel string is elastic. Putting it around a tuner post doesn’t magically stop it from stretching.
But the wrapped portion isn’t simply another 2.2 inches of freely suspended string.
As string wraps around a tuner post, friction between the string and the post transfers load into the post. The entire wrapped length therefore doesn’t necessarily experience the same tension as the freely suspended portion of the string.
More importantly, when conventional tuner wraps cause trouble, it’s often because they were installed badly.
Loose wraps can tighten. Overlapping wraps can shift. A poorly secured string can slip.
That’s different from saying that three neat, tight wraps on a properly strung guitar are inherently unstable.
They’re not.
So Why Do Locking Tuners Help?
Locking tuners are useful.
They make string installation faster and easier. They allow very little string to be wrapped around the post, and they greatly reduce the possibility of a poorly installed string slipping or settling.
That’s good.
But here’s the important part:
A locking tuner does not lock the string at the nut.
The string still passes through the nut slot exactly as it did before.
If that nut slot is binding, installing locking tuners does not make the binding disappear.
And in our repair shop, the nut is one of the first places we look when a guitar has tuning problems.
The Nut Is Often the Real Culprit
Look closely at the nut slots on many production guitars.
The bottom of the slot may run nearly parallel to the fretboard. Then, at the back of the nut, the string suddenly changes direction and heads downward toward the tuner.
Frequently, that rear edge is also quite sharp.
So you have a string under considerable tension being pulled across a small, sharp contact point.
Then you bend a note.
String tension increases on the fretboard side of the nut. Ideally, the string should be able to move through the slot as that tension changes.
But if the nut grabs the string, the tension doesn’t equalize properly.
Release the bend and the string may not return to exactly where it started.
The same thing can happen when using a tremolo.
That’s why a guitar may come back sharp after a bend, flat after tremolo use, or suddenly jump in pitch while you’re tuning it.
That little ping you sometimes hear while tuning?
Pay attention to it.
The tuner may not have moved at all. The string may simply have been stuck in the nut and then suddenly released.
A Properly Cut Nut Is Different
This is one of the details we address during professional setups at Hank’s Guitar Shop.
The front and back of a nut slot have two different jobs.
At the fretboard side, we want a clean and precise witness point. That’s where the vibrating length of the open string begins.
But the back of the nut doesn’t need another sharp edge.
From that front witness point, the bottom of the slot should angle toward the tuner. The rear of the slot should transition smoothly into the string’s natural path, with the tuner-side edge rounded rather than left sharp.
Instead of:
Flat slot → abrupt corner → tuner
we want:
Precise front witness point → gradual slope → smooth rear exit
That seemingly small difference can have a major effect on how easily the string moves through the nut.
And if the string moves freely, it has a much better chance of returning to the same tension after bends, tuning changes and tremolo use.
What About Nut Material?
You’ll see plenty of claims about bone, graphite, synthetic nuts and various “low-friction” materials.
Material can matter.
But we’d rather have a correctly cut slot in a suitable conventional material than a supposedly slippery material with bad geometry.
If the slot is too tight, aimed in the wrong direction, or forcing the string across a sharp rear edge, changing materials may simply give you a different material with the same bad slot.
Correct the geometry first.
Then Why Does a Locking Nut Work So Well?
Now we’re talking about something very different from a locking tuner.
Once a locking nut is clamped, the string can no longer move through the nut at all.
Everything beyond that clamp — the string running toward the tuner, the tuner itself and the tuner wraps — is effectively isolated from the playing portion of the string.
And the biggest source of trouble at that end of the guitar has disappeared:
There is no longer any string sliding through the nut.
That’s why locking nuts are so effective with tremolo systems capable of extreme pitch changes.
Instead of trying to make the string slide through the nut with very little friction, the locking system simply says:
It isn’t going to slide at all.
That’s a very effective solution.
But Compare Apples to Apples
Here’s where locking systems sometimes get more credit than they deserve.
Take a guitar with a poorly cut conventional nut — narrow slots, flat bottoms and sharp rear edges — and compare it with a double-locking tremolo system.
Of course the locking system looks dramatically better.
One system eliminated movement through the nut.
The other has a nut that’s actively fighting the string.
A more useful comparison is a locking system against a conventional guitar whose nut has been properly fitted and properly slotted.
The locking system will still have an advantage during extreme tremolo use.
But for ordinary playing, bending and moderate tremolo use, a well-cut conventional nut can be remarkably stable.
Before You Buy New Tuners, Find the Actual Problem
If your guitar won’t stay in tune, don’t start replacing parts based on internet folklore.
The problem could be:
- Binding at the nut
- Poorly installed strings
- Loose or shifting tuner wraps
- Movement at the bridge
- Improperly secured hardware
- A tremolo that isn’t returning consistently
- Or, yes, an actual tuner problem
The important part is diagnosing the cause before buying the cure.
That’s how we approach tuning problems at Hank’s Guitar Shop.
When we perform a professional setup, we’re not interested in simply getting the strings to the right height and handing the guitar back. The entire string path matters — including the nut slots, their direction, their width and how smoothly the strings travel through them.
The Bottom Line
Locking systems aren’t snake oil.
Locking tuners are convenient and eliminate several potential string-installation problems.
Locking nuts provide a genuine advantage, particularly with aggressive tremolo systems.
But neither changes one simple fact:
A properly cut conventional nut should not be fighting the strings.
Before spending money on replacement tuners or other hardware in search of better tuning stability, make sure the guitar’s existing string path is working the way it should.
Sometimes the best tuning upgrade isn’t a new part at all.
It’s fixing the part that’s already there.
Having tuning problems? Bring your guitar to Hank’s Guitar Shop in Clearwater. We’ll find out what’s actually causing them before we start selling you parts you may not need.
