Can You Put Steel Strings On A Classical Guitar?

It’s never appropriate to put steel strings on a classical guitar. The strings will put far too much tension onto the classic guitar’s light bracing and thin top. Plus, it’s not common for there to be a truss rod on a classical guitar. Therefore, if the steel strings don’t snap the neck off, then it will cause other damage rendering the instrument unplayable.

Always use nylon for a classical guitar and save steel strings for an electric or acoustic one. The only time it might be okay to put metal strings on a classical guitar is if there’s a truss rod designed to support steel strings. But this is even a questionable thing to do.

Can You Put Steel Strings On A Classical Guitar?

What Happens When You Put Metal Strings On A Classical Guitar?

What happens when you put metal strings on a classical guitar will result in irreparable damage. The neck cannot support the weight and pressure of steel. While it may sound great for a brief period, it will ruin the guitar.

Neck, Bridge & Frets

Bridges intended for metal come angled and tapered on the neck of the guitar. This compensates for string thickness and tension. Classical guitars, on the other hand, are straight. If you use steel strings, this will make the higher areas of the neck sound too high and will thusly be unplayable.

The steel strings will also damage the frets on a classical guitar. But, the guitar won’t last long enough for you to see that occur.

At some point the neck will break off. If not, surely it will bend, swell or warp, affecting the guitar’s intonation. As a result, the bridge will rip away from the top of the guitar’s body. This is because steel strings have the capacity to put two times more tension than nylon.


Typically, steel strings place about 160 to 180 pounds of pressure. Nylon, on the other hand, puts on around 80 pounds. Therefore, truss rods and bridges found on guitars designed for steel strings will be far more durable than the standard neck and bridge on classical ones.

Do You Have To Use Nylon Strings?

While nylon is the preferred material for strings on a classical guitar, you don’t have to solely use them. You could also use ones made of a silk core for the bass strings and animal intestines or sinew from deer, cows or sheep. However, this is the traditional material of strings and these are expensive to come by.

Fluorocarbon polymers have made a recent development on the string scene for classical guitars. Actually, luthiers prefer these as they make a nice and smooth transition via the G-string from treble to bass.  

What Guitars Can Use Nylon Strings?

Almost any guitar can use nylon strings but only acoustic and electric can use steel or another type of metal. This means you can put nylon strings on acoustic, classical, and flamenco guitars. While it is possible to use them on an electric guitar, it’s not advisable. This is because these kinds of guitars won’t hold the nylon up very well.

In fact, if you have a guitar intended for steel, the chances of the nylon strings breaking and overstretching often are high. This means you’ll have to replace them frequently and this can get quite expensive.

Having said all that, it’s not advisable to change from nylon to steel strings and vice versa on any type of guitar. This is because the design of each instrument will be most appropriate to one or the other. Plus, when you buy nylon strings, you’re actually purchasing each with different thicknesses appropriate to their individual placement.

How Is A Classical Guitar Distinct From An Acoustic?

The basic distinction between a classical guitar and an acoustic one is its construction. This is what not only determines how it sounds but also what kinds string materials you can use. This relates to hardware, the materials the guitar comprises and every part of its construction.

Variations in Top & Bracing

When you look at the underside of your guitar, the thickness of the top and bracing will reveal the difference between classical and acoustic guitars. Classical ones are smaller and thinner with fan bracing. Acoustics are thicker and heavier with rigid bracing, called “x-bracing.”

The delicate design of a classical guitar’s bracing and top means you have to use nylon or other synthetic material. The more robust design of an acoustic guitar lends itself to requiring stronger metal strings.

Truss Rods

What further determines this distinction is the presence of a truss rod. The neck on most acoustic guitars has a metal beam inside of it, or truss rod. This helps counteract the immense tension given from metal strings. Classical guitars don’t often have this feature because nylon doesn’t deliver nearly as much tension.

Even if a classical guitar has a truss rod, as some modern ones do, it’s not advisable to use metal strings like steel. This is because there isn’t enough strength to counterbalance the tension.


When you combine this with the style of the nut used to keep the strings in place, you can quickly understand how this can become an issue. Using the wrong type of strings on a guitar will always result in poor playability and problems with intonation.

Typically, acoustic guitar nuts are smaller than ones found on a classical guitar. This is because nylon strings are larger and wider, so the nut must be able to accommodate this size. Acoustic guitars have smaller and narrower nuts. This means they may not be able to hold the width of nylon well.


Ergo, never string a classical guitar with metal, like steel. Use nylon strings with classical guitars and steel strings with acoustic ones. This will ensure pliability for years to come. Therefore, as a general rule of thumb, all guitars have the potential to use nylon but only some guitars can use steel.


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