What Is A Tuning Machine Nut On A Guitar?

Did you know there are over a 100 different types of tuning machines available? This is important if you are changing to a new machine because it can affect the value and performance of your guitar.

What is a tuning machine nut on a guitar? Tuning machine nuts are the things that hold the guitar strings to the headstock. This component alters the string tension to correct the notes. Each machine nut has a gear mechanism that attaches to a machine pin that loosens or tightens the strings to find the desired tuning.   

In this article, I will go through this in more detail.  

1. What Is A Tuning Machine Nut On A Guitar?

If you are having problems with tuning your guitar or your guitar maybe slipping its tuning then you have probably come across tuning machine nuts as being one of the root causes. This can be a relatively confusing topic to learn about, just because everyone seems to call the tuning machine a different name. The names include:

  • Machine heads
  • Tuning heads
  • Tuners
  • Tuning machines
  • Tuning knobs
  • Tuning pegs
  • Tuning keys (to name a few)

However, for the sake of this article I will refer to them as ‘tuning machine nut, or tuning machines’ as these terminologies are a very clear reference of what we are talking about.

As discussed, a tuning machine nut is the component of your guitar that corrects the tuning of your guitar by adjusting the tension on your strings.

Tuning machine nuts are located on the headstock of a guitar. A bass guitar will usually have four machine nuts (to accommodate four strings), whilst a standard guitar will have usually have six machine nuts (to accommodate six strings).  

Overall, there are as many tuning machine nuts as there are strings so they could vary dependent on how many strings your guitar has.

2. What Are The Different Parts Of A Tuning Machine Nut?

There are many different parts of a tuning machine. In this section, I go over all the parts. However, it is important to note that not all machine nuts have all these parts as it can be quite dependent on the brand and type of machine you are using.

In section 3, I discuss the Two types of machine nuts. Whereby, knowing all the parts can help you identify which type of tuning peg you are using.

Below, are all the parts that you will find on a tuning machine nut.

  • Tuning head / grip piece – the tuning head is the part of the machine that your hands grip and twist to loosen or tighten the string.
  • Cylinder – the cylinder is the part that holds the string, where the string coils round repeatedly. 
  • Tuning post – the tuning post is the long stem that slots through the headstock borehole.
  • Borehole – The borehole is the hole in the headstock that holds the post.
  • Pinion gear – the pinion gear is the mechanism that is fixed to the tuning post and responsible for turning the cylinder.
  • Worm drive – the worm drive is the gear wheel that attaches between the tuning head / grip piece and pinion gear.  
  • Bushing – the bushing fastens the tuning post onto the headstock from the front side of the guitar.
  • Button – the button is either a screw or indexing pin (depending on the type) that holds the machine in place to prevent any movement and twisting. 
  • Rubber casing (sealed machines tuners) – the rubber casing is only found on sealed machines and they are used to prevent dirt and moisture getting inside, as well as being used to keep the gears lubricated.
  • Locking screw (guitars with a Whammy) – the locking screw is only found on certain guitars (mainly with whammy bars), but adds pressure on the coiled strings to prevent the strings from slipping.

Overall, a machine nut is a cylinder that sits in a pinion gear with a worm drive connecting them. By threading the string through the cylinder, you can tighten or loosen it by turning the tuning knob.

If you require a deeper understanding then please read this article on The Different Parts Of A Tuning Machine Nut as I cover these in much more detail.

3. Purpose Of Tuning Machine Nuts

Every guitar has to be tuned regularly.

This is because the tension of the guitar neck is balanced in coherence to the thickness of the strings.

However, the problem is that tension in the neck can alter can alter many times throughout the day, and this has a direct effect on the strings.

This can be due to everything from the changes in room temperature, to slight knocks and bangs.

Generally, this means you must tune your guitar before you pick it up and play it each day.

With this mind, tuning machines have TWO Main purposes.

The first purpose is to ensure the strings are anchored to the guitar in a sturdy manner to prevent the tuning slipping as best as possible.

Whilst the second purpose is to ensure the guitar can be re-tuned quickly and easily when the tuning has slipped.  

#Purpose 1 – Firmly Anchoring the Strings To The Headstock

The better the quality of the tuning machines the better they hold the tuning.

This is why your guitar needs to have good quality machines as it does make a tremendous difference to the quality of your tone (I discuss more about this in section 5).

#Purpose 2 – Flexibility In Tuning & Re-Stringing

The tuning knob loosens and tightens the strings by adjusting the tuning head / grip piece.

The tension in the neck of the guitar will alter hundreds of times throughout the day. As it does the tuning may slip from time to time even whilst you are playing.

Therefore, it is necessary that the tuning machine provide flexibility as the turning will be altered even whilst you are playing.

4. What Makes A Quality Tuning Machine

I will go through the range of tuning machine nuts below. But, before I do there is something that is important to note; this is understanding the materials tuning machine nuts are made from.

A sturdy machine nut is important as this required to hold the tuning.

When looking into the range of these we need to understand that the better quality tuning machines are made from stronger and sturdier material.

This comes down to the manufacturing and the materials it is made from.

You can often tell the sturdiness with a quick observation.

High Quality Machine Nut

The high quality nuts will not rust and not break from general wear and tear, and so long as you use a popular brand, the machine will be of high quality.

Popular brands can include: 

  • Waverly Machine Nuts (Hand-made in the USA)
  • Grover Machine Nuts (Made in the USA & China)
  • Schaller Machine Nuts (German manufacturing)

These brands are manufactured to a high quality and the materials they use are a stronger material.

The high quality machine heads are made from a hard durable alloy steel and plated in either silver or gold. 

Low Quality Machine Nut

The low quality nuts will not last too long and you will see signs of breaks and rust after 2 years.

Not only that they just do not feel solid, but more fragile and tacky.

This is because they are made from either plastic or a low quality or-plaque metal.

As well as struggling to find the tuning, you will also find these machines will not hold the tuning as well, as they tend to bend under the tension of the guitar strings.

By having, a machine head that does not have any brand engraved onto the metal will usually indicate a cheaper low-end machine.

5. What Are The Types Of Tuning Machine Nut?

There are many types of tuning machine nuts.

These are usually broken down into vintage sealed units, however there are other variations of these types.

Sealed Machines

Sealed machines are the more modern type of machine heads that protect the gears with a protective housing.

Vintage Open-Backs

Vintage open-backs are the traditional first wave of tuners. This holds sentiment to collectors but generally do not last as long because the exposed gears will get damaged from general wear and tear over time.   

Vintage Closed-Backs

Vintage closed backs are still the same fitting as the vintage open-backs but have the additional benefit of the protective housing. 

Side-Mounted Machine Heads

Side-mounted machine heads are similar to the vintage open backs however they have a slightly different fitting being lacked onto the side of the headstock.

Lock-In Heads

Lock-in heads are basically the same as the sealed machine but they have an additional component that locks the strings into place.

I have covered all the different Types Of Tuning Machine Nuts here if you require a more detailed explanation so please visit.

6. What Are The Best Tuning Machines?

The best tuning machine is very dependent on your objective. A guitarist objective usually comes down to one of the following three reasons…

  • The best tuning machine for appearance
  • The best tuning machine for functionality
  • The best tuning machine for collectability

I will go through all these reasons below…

The Best Tuning Machine For Appearance

When it comes down to appearance, it is very a subjective topic. I have found this is really determined by the genre of music you like to play and who your influences are.

For example, if you are an old school blues rocker then you will probably prefer the more traditional vintage machine heads, whilst classical finger picking players will prefer the appearance of side-mounted machine heads.

I personally prefer the sealed machines because they are tidier. I find the strings can get easily messy (especially after re-tuning), and so having an open-back tuning device is just too much for me.

I also know some players like to keep the whole of the strings present after retuning and like to embrace the more creative look. 

The Best Tuning Machine For Functionality

The best machine tuners for functionality are without a doubt the sealed machine tuners.

Having everything sealed away in a protective housing keeps the gears protected from dirt and debris as well as being lubricated for a long lasting smooth feel.

However, there are a whole range of brands out there, some cheap brands (that are not advised) and will probably only last a few years as well as not keeping your guitar in tune as well.

As discussed, if the tuning machine does not have any engraved markings then they are probably a cheap brand.

You can spend more money for acquiring Gotoh tuners and if you really want to go crazy then check out Waverly tuners (3x the cost of Grovers!)

Nevertheless, you get what you pay and there is something special about having a hand-made Waverly.

The Best Tuning Machine For Collectability

If you have an old vintage guitar and it is for show then it is no brainer to keep it original with vintage open-back tuning nuts.

Ensuring you keep the original vintage tuning nuts will keep the value of the guitar.

Actually, changing these tuners to a sealed machine will actually devalue a vintage guitars worth forever. This is because the bushing holes on the headstock will have to be enlarged in order to install the new sealed bushing.

As well as new screw holes will have to be drilled.

These modifications cannot be reversed, even after you convert them back.

7. Why Do Tuning Nuts Send Your Guitar Out Of Tune

No matter what type of tuning pegs you prefer the tuning nuts is a good place to start trouble shooting if your instrument goes out of tune.

Common reasons why your guitar goes out of tune because of the tuning machine is as follows:

  • The strings may not be wound tight enough around the tuning peg. This will cause the strings to go flat as you play.
  • The gears inside the tuning machines wear down from the immense string tension, which can cause them to give. Gears can also strip or skip teeth, which simply means they need replacing.
  • The tuners are not anchored tightly onto the back of the headstock, which affects tuning stability

At the end of the day, the tuning keys should not be overlooked. Proper maintenance to this rather innocuous part of the guitar will keep you sounding your best.

I have wrote an article explaining why tuning machines effects your tuning in more detail so please check it out.

8. How A Tuning Machine Nut Is Used?

Tuning machine nuts work by anchoring the strings into place by threading the string through the cylinder. As the strings thread through the cylinder they overlap (like fishing wire on a fishing rod).

As you coil the strings, the tension that is created is what locks the strings into place. Thus, holding the strings in place.

You turn the tuning-head clockwise to tighten it and anti-clockwise to loosen it.

When you have a new set of strings they can stretch and so you can pull on the strings slightly (always tuning up) to ensure a solid tuning.

You never want to tune down as this does not hold the tuning as well as you want to avoid over stretching the strings as this can weaken them. 


In this article, I have covered in brief everything you need know to understand the basics of tuning machine nuts including:

  • What Are The Different Parts Of A Tuning Machine Nut?
  • Purpose Of Tuning Machine Nuts
  • Locking Screws & Tuning Machine Nuts
  • What Materials Are Quality Tuning Machine Nuts Made From
  • What Are The TWO Types Of Tuning Machine Nut?
  • What Are The Best Tuning Machines?
  • How Do Tuning Nuts Send Your Guitar Out Of Tune
  • How A Tuning Machine Nut Is Used

Overall, that there are two main types of tuning machine nuts which both breaks down into many other variations.

I hope you liked this article, if you have any questions, or you are a bit confused about some of my explanation then please leave a comment of your query.

Thank you for reading this far and I hope you have a great day!

Rich Wilde Music

My name is Richard Wilde and go by @richwildemusic on all major social channels. I am an artist, guitar player, and producer. I have been playing guitar for over 15 years and have come to learn the "tips" and "tricks" to enhance guitar playing, recording guitar, setting up guitar, and overall get that professional sound.

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