I know that putting a steel string on a classical guitar is not advisable as it can damage the bridge or the neck. And based on my research classical guitars doesn't have truss rods because nylon strings does not put heavy tensions ..

But i was surprised on the classical guitar that i bought because it has a truss rod in it. So i was wandering if i can put a steel string on it, because i think that the neck can handle the tension. And what about the bridge? I think that classical guitar's bridges is different from acoustic guitar's bridges.

So, is it safe?

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    Why do people keep wanting to do this? "It's a bad idea", we say. "But this time it's different!", they say. Dec 10, 2014 at 20:46
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    I've got to say, I agree with @VarLogRant here. If you want to put steel strings on an acoustic guitar, you're best putting them on a steel-string acoustic guitar. Dec 10, 2014 at 23:21
  • Agree too. Why would you want steel strings... though allright, if you want a brighter sound, extended bending range and/or magnetic pickups, then you can actually put steel strings on any classical guitar – just, definitely not the standard western-guitar kind, but specially designed low-tension rope strings, like the Thomastik Classic S. Dec 10, 2014 at 23:47
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    possible duplicate of Can I use nylon with steel string guitar?
    – Neil Meyer
    Sep 20, 2015 at 7:33
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    I've voted to leave this open. Although these questions are related, the consequences of the actions described are very different. Sep 20, 2015 at 10:47

11 Answers 11


This is not only about the neck. The pattern of bracing under the top, and the bridge plate under the top of your classical guitar, are designed to vibrate with and counteract the tension of nylon strings. Steel strings have twice the tension, so steel strings would cause the top of the guitar to warp upward, or "belly up" and eventually the bridge would rip loose from the top. This would destroy your guitar.

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    I understand that the frets are generally of softer material and will tend to get tore up by metal strings. Dec 10, 2014 at 20:47

Classical guitar truss rods are not designed for steel strings - I learnt this as a child when my classical (with a truss rod) ended up with a bent rod and cracked neck.

  • I've never seen a classical guitar with a truss rod.
    – user50691
    Dec 2, 2018 at 2:16

I did this once back in my younger years. The guitar did sound awesome, but over time it destroyed the structure and integrity of the instrument. I would not advise steel strings on classical guitar, unless you don't care about the instrument. Try some hard tension nylon strings instead.


Another problem with adding steel strings to nylon string guitars comes in the form of "how far from the neck the string is." A steel string guitar has the string very close to the neck so that it is playable, whilst a nylon string guitar has it a fair way from the neck so that it plays louder. There is quite a bit of theory involved here, but in simple terms, the nylon string guitar that has steel strings on it, if it was able to cope with the forces, would be very hard to play and not sound great at all.

  • Or (what I do), you lower the fret 0 and the bridge. You reduce the tension all of you speak about (actually, you reduce the tension momentum, but that's it, no?) and the guitar survives for ages. Many Czech people do it because during the communist era, you didn't have many western guitars in the shops and people still wanted to play steel strings.
    – yo'
    Dec 11, 2014 at 7:36

The key is the string tension being similar to nylon strings. This will mean that you will have to do some calculations to determine the proper gauge strings to produce the notes at the tension that is safe. This D'addarion web site should help you in your endeavor...


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    Could you maybe explain how to use that website for this task? This post was flagged as spam, and we generally discourage answers that primarily rely on a link.
    – user28
    Nov 11, 2015 at 18:56

The answer I have found works well is to use Newtone Heritage strings .010 to .043 gauge. These are "normal" steel and phosphor bronze - low tension - acoustic guitar strings and are hand wound in England. They have almost equal tension and although ultra-light gauge their total load is 94 lbs and therefore only slightly more than a set of low tension nylon strings. I have them on a lovely modern handmade Spanish guitar (Antonio Picado Model 49 2004) with a cedar top and Indian rosewood back and sides and the resulting sound is crisp and resonant - lovely for fingerpicking and arpeggios and very loud - certainly louder than my Martin D18 GE though without the woody bass from the Mahogany back. Lots more finger room and works well with an LR Baggs classical under saddle pickup. A good classical guitar can be very loud even with nylon strings and is more so picked with just bare finger pads.

Of course I agree that this is something that should not be tried on a very old or valuable or treasured classical guitar or one with repairs and that there are risks but Newtone Heritage strings are designed for those older Martins without truss rods that re often heavily repaired and they are loud and easy on these old fingers to. If you don't mind accepting the slight risk of a 12% overload (surely within design limits of a modern classical guitar?) then this produces awesome sound and playability in my opinion. I would not however put them on my treasured 1970 Taurus (also made by Senor Picado I believe) as it has already been driven over in its youth while on loan to my sister-in-law!

By the way, I have no connection with Antonio Picado or Newtone Strings other than being a very satisfied customer of their Materclass, Heritage and Mandolin family strings! They can be difficult to track down in the right gauges, presumably because they are different (being on round wound cores) and popular.

Ian Kirkland


As others have pointed out, this is probably a bad idea. If you still want to consider it, mind the string tension. A typical nylon strings set has a total tension of around 80 pounds. You definitely don't want to replace that with a typical acoustic steel set, which is almost double that.

Some electric guitar strings, e.g. D'Addario EXL130 or EXL120, are in a safer range (70-85 pounds). Still not sure how well they might work.


My workplace has a guitar I just used today - it has steel strings although it is a classical guitar. I noticed a couple of tuning pins already "loose" (spinning with no increase in tension on the string) and has very little volume or tone to the strings. Very hard on the fingers because of the height of the string. I would not recommend a normal set of steel strings on a classical, as people have already mentioned. It was tough to play and not particularly enjoyable either.

Not sure how long the strings have been on for - am thinking the problems suggest there is some damage to the guitar's structure. Now I'm wondering if putting nylon strings back on it will work? Will I break the neck taking the steel string off? I always replace one at a time, but the difference in tension will be very different. Any ideas?

Thank you and hope I answered, and am able to ask at the same time??

  • @K Morris if you want to ask a question, you can do it by clicking on the 'Ask Question' on the top right of the site. This space is for the answers to this question Sep 26, 2016 at 12:01

I put some higher tension strings on my classical guitar, a Córdoba, and they were on for maybe less than a year and the bridge snapped off. There could have been other factors to this, but I imagine steel strings would be worse.


To answer the OP - the short answer (as others have aptly stated) is a big fat NO. Don't do this. You will ruin the guitar.

As do why you would want to do this - if you are looking for a wider neck than a standard acoustic (or electric) guitar you could look into acoustic models that have a wider neck. This allows for the steel-string tonality while allowing for fingerings more like a classical.


Yes you can just put steel strings on a classical guitar if you really want to. They will of course create some structural and playing issues though.

The far greater string pressure on the classical guitar's plastic machine-head winder barrels will probably crack some of them fairly quickly, but they will still work.

The classical guitar's body, being constructed of much lighter/thinner woods and lighter wood bracing on the inside of the soundboard wont help either.

The soundboard top behind the bridge will rise to some degree ("bellying"), depending on the guitar. That will raise the height of the strings above the fretboard making it even harder to play and the string height will already be quite high.

The best thing to do would be to only tune the steel strings to a whole tone down from concert pitch "C", which would really lower the strain on the guitar's body. Put a capo just behind the second fret if you wish to play in concert pitch.

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