Forum: music.stackexchange.com
Tags: <strings><acoustic-guitar>
Title: Why does the D string in a guitar breaks so often?
Question: Well... that's about it. D strings (on acoustic  nylon  guitars at least) break way more often than the others.I guess there's a physical explanation but I wasn't able to found anything on the Internet. Do you guys know why this happens?

Answers:
sents: text: First, I agree with the question, when talking about nylon-stringed guitars - in nearly a half-century of playing classical and flamenco instruments, I find that the D string, the poor thing, breaking more frequently than any the others (other answers and comments are probably based on steel-stringed experience).
text: I've asked luthiers, and even one of the D'Addario sons :-)
text: about this, and there are a number of causes (besides flaws in the guitar itself): The D is a wrapped string, and more likely to break than a solid string
text: It has thinner wire than the other two bass strings
text: It is under the highest tension of the three bass strings
text: It gets more wear than the other three (think about melodies you've played on that string
text: - it's the brass section of the guitar).
text: Of course, replacing your basses frequently will usually save you the embarrassment of changing strings on stage
text: (I had to do it twice with a D string recently, because I botched the first stringing job -
text: oh well).
text: The goal is to keep them from breaking, until they finally "wear out" - the basses start to sound like rubber bands.
text: So what can you do about that?
text: As I said, change the basses before one breaks.
text: Besides the sound going bad, look for the finish wearing off.
text: And here's a trick - if you take them off before they get really worn, you can put them back on again later, and they will not only sound great for a short while, but because they are "pre-stretched", they will settle in tune much more quickly.
text: It's very helpful to have a "rested" set of basses like this to put on just before a gig (or, gulp, during one...).
text: Make sure that the loop at the bridge is as close as possible to the wood - look at the bass strings in the picture below, note how snug against the wood the loop is.
text: Push it back and down with your nail as you tighten the new string.
text: If you leave it floating half-way between the wood and the ivory, it is putting a lot of pressure on the middle of that short stretch of string, essentially trying to cut it in half.
text: My D's would often break right there, until the luthier/engineer John Gilbert told me what's what.
text: If the D string still tends to break at that spot before it wears out - perhaps because of the construction of the bridge, or because you are using very high tension basses - you can do what I do on a particular instrument, and protect the D string with a very short piece of narrow rubber tubing that can cover the D between the wood and the ivory - the loop cuts into the rubber, but not the string.
text: And where does one find such a thing?
text: Why, strip the insulation off some wiring that's slightly thicker than your D!
text: Good luck, and may your bass strings always maintain their composure when you are playing for people...
answer_details: author: music.stackexchange.com/users/951/WildGeese
score: 16
sents: text: IMO frequently broken strings indicate a mechanical problem.
text: I never break strings
text: and I haven'tt broken one for maybe 30 years.
text: Causes include: Too-sharp edge on nut or saddle.
text: burr or sharp edge on a tuning post, or the hole though same.
text: Nut slots cut too wide (or maybe you installed lighter strings) allowing the string too much side-to-side movement.
text: etc, etc
text: ...
text: Of course, if you really flail away at the strings while strumming...
answer_details: author: music.stackexchange.com/users/549/M. Werner
score: 13
sents: text: From m practice, This is definitely true for nylon strings and this happens because of structure of D-string.
text: The first 3 (E,B,G) are solid, and next 3 (D,A,E) consist of thin nylon fibers wrapped around one more think string.
text: For the D-string the number of fibers is much less then for A and E (because it needs to vibrate in certain range) and this makes it the weakest.
text: When I would buy strings, I'd always buy couple of spare D-strings...
answer_details: author: music.stackexchange.com/users/1362/Michinio
score: 5
sents: text: How often is "often"?
text: If you find that your D string is breaking a lot, there could be an issue with the guitar.
text: Does it break near the tuning post?
text: If so, there could be an issue with the nut slot.
text: If it is near the bridge, it could be something in that area - something sharp that is compromising the integrity of the string.
text: I think most guitarists would say the 1st and 2nd strings are the most common strings to break in the course of regular playing.
answer_details: author: music.stackexchange.com/users/944/vjones
score: 3
sents: text: A couple of things could be at issue.
text: Since it's always the same string, my guess is that there's some tiny discontinuity at either the nut or the bridge (whereever it's breaking)
text: where the string is snagging (unless it's a "locking" system, the string should slide freely).
text: Fix:
text: Whenever you change a string, take a pencil and scribble all over the path of the string (at the nut, bridge, and tuning post.
text: NOT the fretboard or the top!).
text: The graphite will work like a permanent lubricant.
text: Tuning issues.
text: It may not seem relevant, but have you ever taken a steel spoon at school or camp and bent it back and forth until you can snap the head off?
text: Little mistreatments of the strings can add up quickly.
text: Always tune up into the note.
text: So if you're tuning the D string to a tempered fourth above the A string, tke it to a perfect fourth and nudge up for the temper.
text: But to tune the low E to a tempered fourth below the A string, you need to scoop in from D# and stop short of perfect, obtaining the temper by "subtractive geometry".
text: Always tune to the same pitch standard.
text: If your friends use A-440, use A-440.
text: But if you also want to play regularly with your friend's A-435 piano, you really need a second guitar for that.
text: The strings won't know where their "home" is.
text: One more thing.
text: There could be something in the atmosphere that interacts badly with the metal of the string.
text: Trying a different metal (bronze, steel, nickel) or a different alloy (the ratio of metals) might help.
answer_details: author: music.stackexchange.com/users/1344/luser droog
score: 2

Summary of the answers:
The D string may break more frequently because it has thinner wire the the other bass strings and it is under the highest tension. However, frequent breaks may signal a problem with the guitar, such as something sharp in the bridge area or a mechanical problem. Moreover, something in the atmosphere could be reacting badly with the string metal.
There are a number of potential reasons by the D string might break more often on a guitar. Firstly, the D string has a thinner wire than the other two bass strings, and secondly, it is more tense than the other two bass strings. However, if it is breaking frequently, this could indicate a mechancial problem with the guitar.