IS THIS TRUE??

[robj144]

Originally Posted by rick-slo

First see my prior link: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

There are several different alloys of stainless steel and they vary widely in properties such as tensile and elastic limits. Exactly what is used for guitar
strings I don't know, but as I said prior it probably has properties similar to piano wire.

I didn't even see the first time I looked though. That's the tensile strength. The yield strength is less than that.

[rick-slo]

Originally Posted by robj144

I didn't even see the first time I looked though. That's the tensile strength. The yield strength is less than that.

Yes, I mentioned that in my prior thread. Elastic yield strength versus ultimate stress varies with the type and alloy of metal.
Here is a chart of some metals listing these values:
https://www.engineersedge.com/materi...d_strength.htm

Note in particular 2800 Maraging steel and how close the two values are. Of additional interest regarding this the American musical
instrument string producer, Ernie Ball, has made a specialist type of electric guitar string out of Maraging steel, claiming that this
alloy provides more output and enhanced tonal response.

[Glennwillow]

Originally Posted by rick-slo

I have not found metal properties specific to guitar strings on line but it is probably the in the same range as piano string wire (and for the same reasons).

See: https://ef.engr.utk.edu/ef152-2015-0...in-elastic.pdf

The data on the above link would give for example an ultimate strength limit of 43.791 pounds of tension for a 0.013" guitar string. So for example tension wise on
a 25.5" scale guitar that is equivalent to the high E string tuned up to about G#, not that I would ever do that. For elastic limit, again no specific data for guitar
strings but using high strength steel as an example the elastic limit would be about 39 pounds (high E tuned up to about G).

This is interesting.

According to the tension charts published by D'Addario on their downloadable PDF document the normal tension of a high E string tuned to E=329.6 Hz is 27.4 lbs.

My own experience with the yield strength of steel is that about 80% of the tensile strength is a typical approximation. Using Rick-slo's numbers above for tensile strength, 43.791 x 0.80 = 35 lbs at yield for a 0.013" high E string. Rick had found 39 lbs for high strength steel, fairly close to and reasonably consistent with my 35 lb approximation. If either of these numbers are correct, then 27.4 lbs for the high E string tuned to a normal E=329.6 Hz is at about 78% of yield strength using my more conservative 35 lbs number.

So these numbers don't suggest that the highest stressed high E string is being tensioned to beyond the yield strength of the metal.

- Glenn

[rick-slo]

Originally Posted by Glennwillow

This is interesting.

According to the tension charts published by D'Addario on their downloadable PDF document the normal tension of a high E string tuned to E=329.6 Hz is 27.4 lbs.

My own experience with the yield strength of steel is that about 80% of the tensile strength is a typical approximation. Using Rick-slo's numbers above for tensile strength, 43.791 x 0.80 = 35 lbs at yield for a 0.013" high E string. Rick had found 39 lbs for high strength steel, fairly close to and reasonably consistent with my 35 lb approximation. If either of these numbers are correct, then 27.4 lbs for the high E string tuned to a normal E=329.6 Hz is at about 78% of yield strength using my more conservative 35 lbs number.

So these numbers don't suggest that the highest stressed high E string is being tensioned to beyond the yield strength of the metal.

- Glenn

Yes, and for 2800 Maraging steel which I referenced above (and which Ernie Ball has been using lately) the tension and elastic limits for a 0.013" string are 53.5 lbs. and 52.0 lbs. respectively. Of course those extra high limits could allow for guitar destruction in the hands of a haphazard guitarist tuner.

[Rodger Knox]

I don't remember where I read it, but I remember concert pitch being about 80% of yield strength. It may have been String Theory on Al Carruth's site. That seems to agree with some of the numbers posted above.

Originally Posted by zmf

If a guitar were strung with strings of a non-elastic material, and tensioned below it's breaking point, it could not produce a given pitch -- i.e., oscillate appropriately -- when plucked?

There's no such thing as a non-elastic material, but if their was, it could not vibrate because that requires variation in the length of the string which would not happen without elasticity.

It Theory, there's no difference between theory and practice. In Practice, that's not always true.

[zmf]

Originally Posted by Rodger Knox

I don't remember where I read it, but I remember concert pitch being about 80% of yield strength. It may have been String Theory on Al Carruth's site. That seems to agree with some of the numbers posted above.

There was a mention of non-elastic material in one post. That does not exist, except maybe for liquid, and even that has a bulk modulus of elasticity.

The non-elastic post was by me, and it was meant as a hypothetical, since I have zero engineering background. It's interesting to know that all solids have elasticity.

On the issue of whether guitar strings stretch when tuned to pitch, I'm guessing that they might, given that there is elongation at tensions less than "yield strength"(?)

And (after your edit) a string must elongate when vibrating. So a "steady state" elongation from tuning, and an additional transient elongation when vibrating?

[rick-slo]

Originally Posted by zmf

On the issue of whether guitar strings stretch when tuned to pitch, I'm guessing that they might, given that there is elongation at tensions less than "yield strength"(?)

A string stretches elastically under tension. There has been no disagreement about that. However some seem to think that at the usual range of guitar tunings
strings not only stretch elastically from the tension but under go a slow, but permanent deformation from that tension.

[zmf]

Originally Posted by rick-slo

However some seem to think that at the usual range of guitar tunings strings not only stretch elastically from the tension but under go a slow, but permanent deformation from that tension.

That does seems to be the question of practical interest.

Appreciate the patience with my naive questions. It was in part to push for an answer to this question.

[Rodger Knox]

Originally Posted by zmf

The non-elastic post was by me, and it was meant as a hypothetical, since I have zero engineering background. It's interesting to know that all solids have elasticity.

On the issue of whether guitar strings stretch when tuned to pitch, I'm guessing that they might, given that there is elongation at tensions less than "yield strength"(?)

And (after your edit) a string must elongate when vibrating. So a "steady state" elongation from tuning, and an additional transient elongation when vibrating?

I thought you were positing a hypothetical. Mechanics of materials is actually not all that complex, but there's a few basic concepts that are not intuitively obvious.

Originally Posted by rick-slo

A string stretches elastically under tension. There has been no disagreement about that. However some seem to think that at the usual range of guitar tunings
strings not only stretch elastically from the tension but under go a slow, but permanent deformation from that tension.

I'm going to agree and disagree, as a matter of perspective. A slow permanent deformation from tension below yield strength is often called "cold creep", which does occur in steel. Cold creep in wood takes years, usually decades. With steel, it would be centuries or millennia, so for practical purposes, steel does not cold creep.

Originally Posted by zmf

That does seems to be the question of practical interest.

Appreciate the patience with my naive questions. It was in part to push for an answer to this question.

I don't believe that guitar strings are ever tensioned beyond their yield strength, so there is never any permanent "stretching". I could be wrong about that, but that's what the numbers I've seen lead me to believe.

[rick-slo]

Originally Posted by robj144

And here:

https://www.makeitfrom.com/material-...500-Music-Wire

Sorry, missed this post and link earlier. Good info on that link

With that metal the elastic yield limit for a high E 0.013" plain string would be 39.81 lbs. (or around a G# note on a 25.5" scale).

[rick-slo]

Originally Posted by Rodger Knox

A slow permanent deformation from tension below yield strength is often called "cold creep", which does occur in steel. Cold creep in wood takes years, usually decades. With steel, it would be centuries or millennia, so for practical purposes, steel does not cold creep.

I and my guitars can live and die within those time frames. No problem

[Silly Moustache]

Hi, me again. I've been hiding under the table because I don't understand all this.

I hadn't intended to fire up a dialogue about elasticity, or breaking points, although if you have enjoyed that aspect - fine, but don't lets make this discussion turn into an argument.

However my question was the whether it is considered that strings, once put on a guitar, lose tension, because that was what I saw someone stating on a YouTube video about setting up guitars.

I can't find it now, but it is probably best to allow him anonymity.

[rick-slo]

Originally Posted by Silly Moustache

Hi, me again. I've been hiding under the table because I don't understand all this.

I hadn't intended to fire up a dialogue about elasticity, or breaking points, although if you have enjoyed that aspect - fine, but don't lets make this discussion turn into an argument.

However my question was the whether it is considered that strings, once put on a guitar, lose tension, because that was what I saw someone stating on a YouTube video about setting up guitars.

I can't find it now, but it is probably best to allow him anonymity.

Your original post read differently

Originally Posted by Silly Moustache

Looking for some info on YouTube yesterday, and found a chap talking about guitar set ups.
He said "New strings are at the highest tension then lose tension as they age!"

Really?

Whadya think?

This is what most of the replies were directed at.

[Glennwillow]

Originally Posted by Silly Moustache

Hi, me again. I've been hiding under the table because I don't understand all this.

I hadn't intended to fire up a dialogue about elasticity, or breaking points, although if you have enjoyed that aspect - fine, but don't lets make this discussion turn into an argument.

However my question was the whether it is considered that strings, once put on a guitar, lose tension, because that was what I saw someone stating on a YouTube video about setting up guitars.

I can't find it now, but it is probably best to allow him anonymity.

Hi Andy,

I believe that the answer to whether strings lose tension depends on whether the cross-section of the string is reduced over time. That can happen only if the strings are stretched beyond their elastic limits and permanently deform by elongating permanently. The calculations presented by Rick-slo and Robj144 suggest that the strings on a normally tuned guitar are tensioned below the string elastic limit. To me, that means no permanent elongation of any strings and therefore no reduction in string cross-section.

There is permanent deformation across the saddle and around the tuning posts, but those small areas are not going to affect the cross-section of the string in between the saddle and the nut.

That is my take on this discussion, at any rate.

I hope you are well, Andy!

Thanks,
Glenn