Not if the slot is cut correctly. The string only cares about the surfaces it actually touches.

A customer recently called my attention to a competitor’s guitar repair website where they claimed that nut slot walls higher than the string center, “trap the strings”.

We chuckled about that bit of misinformation, but then I remembered I’d heard this “old wive’s tale” before. So I figured an article was called for..

Nut slot walls could be a mile high without affecting the strings! The strings make no contact with nut slot walls beyond the string diameter center. if they don’t contact the slot walls, they can’t be affected by them!

A guitar string does not become trapped simply because the nut slot walls rise above the centerline of the string. That claim sounds logical until you look at the geometry.

They do not touch the string. If they do not touch the string, they cannot bind it.

For the slot walls to “trap” the string, they would have to touch the string on the sides with enough pressure to create friction. But in a properly cut nut slot, the string rests on the bottom bearing surface of the slot. The upper walls are just clearance.

They do not touch the string. If they do not touch the string, they cannot bind it.

It does cause concern that people are putting themselves out there as “professional guitar techs”, who don’t understand even the fundamentals of guitar geometry.

The real problems with nuts are:

Too narrow
The slot squeezes the string. (Cut for the wrong string size)

Wrong angle
The string does not break cleanly toward the tuner.

Sharp rear slot edges

Slots should be slightly rounded at the rear so strings won’t bind

Rough or dirty
The string grabs inside the slot.

Too low
The string buzzes or rattles on the first fret.

Too high
The guitar plays sharp and feels stiff in the first position.

But “slot wall above the string centerline” is not automatically a problem.

It does cause concern that people are putting themselves out there as “professional guitar techs”, who don’t understand even the fundamentals of guitar geometry.

What Actually Matters in a Nut Slot

Overcut: lowering the slot walls is not the same as cutting the slot correctly.

A nut slot is not wrong because you can see material above the string. It is wrong only if that material interferes with the string.

Why This Matters

A lot of guitars come in after “professional setup” work with nut slots that were treated like shallow little half-pipes. The tops were filed down, but the actual slot geometry was never corrected, and strings sometimes jump out of the slot!

That may look clean, but looks are not the point.

The string needs:

support at the front edge of the nut, a bit of clearance along the sides, a smooth path through the slot, and a clean downward break angle toward the tuner.

That is what affects tuning stability, pitch accuracy, and feel.

At Hank’s Guitar Shop, we don’t guess at nut slots. We check the actual string path, slot width, height, angle, and contact points as part of a proper setup.

If your guitar binds, pings, plays sharp near the nut, or won’t stay in tune, bring it in. We’ll show you what’s really happening.