What Strings Do Classical Guitars Use? (String Guide)

If you’re new to the guitar, you might be confused by some of the terminology, especially around what type of strings a particular kind of guitar uses.

For example, a common question new players might have is: what strings do classical guitars use?

Classical guitars evolved in the early 19th century and used strings made from animal intestine, as did most guitars until the early 20th century when steel strings became widely available. Classical guitars continued using gut strings, but in the mid 20th century, nylon strings replaced those made from gut. 

Let’s take a closer look at how the classical guitar evolved, as well as what kind of strings are best to use on a classical guitar.

Why Do Classical Guitarists Use Nylon Strings?

The guitar is a very old instrument indeed, with its basic design dating back hundreds of years. In fact, the instrument far pre-dates the invention of steel strings.

The earliest six-string guitars appeared in Spain in the late 18th century into the early 19th century. They were based on earlier instruments, but over the course of decades, the basic shape and construction we would recognize today were established.

From the beginning, nearly all guitars were strung with gut strings, but following the advent of industrial production, steel strings were developed in the late 19th century.

Steel strings made playing guitar in front of a crowd more feasible, as the strings produced a louder sound and offered far more sustain than gut strings did. They also put far more tension on both the body and neck than gut strings.

That required better bracing for the body and also led to reinforced necks and, eventually, the modern adjustable truss rod.

Most guitars built for gut strings retained the more traditional style of fan bracing and features like a neck heel made from multiple pieces of wood. As the steel string acoustic evolved, some players still preferred the Spanish guitar, as the classical guitar was often known at the time.

Andres Segovia, for example, became one of the most important names in classical guitar history. He arranged pieces originally written for other instruments for the guitar, and is considered one of the fathers of the classical guitar genre.

He was also deeply involved with the design and construction of classical guitars and was even responsible for the popularization of nylon strings.

Nylon is a synthetic material invented by DuPont in the 1930s. It was used to make everything from women’s stockings to monofilament fishing line.

During World War II, the animal intestine used to make instrument strings was needed to make surgical sutures instead, leading to a shortage. Segovia was one of the players who advised the manufacturer to make sure new strings made from nylon offered the tone classical players were expecting.

Can You Put Any Strings On A Classical Guitar?

As I noted above, steel strings put much more tension on both the body and neck of the guitar than gut strings did.

That’s why it’s very important to know what kind of guitar you have before choosing strings. For example, before the early 1920, no Martin guitar was designed for steel strings, and it wouldn’t be until years later that all of the company’s guitars were made that way.

It’s very very important to never use high-tension steel strings on a classical guitar, or any guitar not designed for them.

This video shows what could happen if you string a classical guitar with steel strings.

There is the possibility of short-term damage by lifting up the bridge of the guitar, as well as long term damage caused by the neck bowing from the extra tension from the much heavier strings.

You could also cause the top to warp or crack, or cause one of the inner braces to come loose, depending on how the tension is distributed.

Can You Use All Nylon Strings On Classical Guitar?

If you know that you can’t use steel strings on a classical guitar because of the excess tension, you might wonder whether there are any other restrictions you need to be aware of.

In general, there aren’t many restrictions other than using nylon strings or another kind of low tension string.

Many modern classical string sets are actually made from fluorocarbon rather than nylon, and you can still find makers of gut strings, as well.

But all of those strings will work on a classical guitar without any issue. One thing that is noticeable when it comes to strings is the color.

Many traditional classical strings are clear, for example, while other strings, sometimes pitched as “folk” strings are black. Willie Nelson, for example, plays a string set with black treble strings.

While there might be some tonal differences between those string sets, the difference will not be enormous, and the tension is similar across the spectrum of non-steel strings.

One of the largest differences between nylon string sets is those that come with ball ends and those that come in the traditional tie style. Ball end strings can be used in a standard classical guitar bridge, for example, but can also be used in the pin-style bridge of a standard acoustic guitar.

Traditional strings, however, are tied to the bridge. This video walks you through the procedure.

What Is A Normal Gauge For Classical Guitar Strings?

Unlike steel string guitars, which categorize their strings based on the gauge, classical guitars categorize their strings based on the tension they put on the neck.

In practice, this is close to the same idea, as thicker strings generally put more tension on the instrument than thinner ones when tuned to the same pitch.

But while steel strings have generally accepted gauge categories, from extra light to heavy, non-steel strings are normally classed as light, normal, hard, and extra hard tension.

The exact gauges of the strings depend on both the composition and the maker. For D’Addario, for example, which makes a wide range of nylon strings, the high E string on a hard tension nylon set has a diameter of 0.029”, while a carbon set has a high E string of 0.025”.

This chart looks at the tension for one line of D’Addario strings, the Pro-Arte Nylon line.

Conclusion

The history of classical guitar making is extremely complicated, and there are many niches and specialties when it comes to the instrument.

And while some people might still argue that gut strings sound the best, it was actually Spanish fishermen who probably first used monofilament nylon fishing line to string their guitars, meaning there is a long history of using synthetic strings.

The vast majority of guitars sold today are made to use steel strings, but there are still many options available for classical guitar players, whether they prefer old-fashioned gut, nylon, or an ultra-modern composite material for their strings.

James Kelly

I’ve been a musician, particularly a guitarist, for more than 25 years. I love writing about guitars, gear, recording, music in general and more.