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Specialty Chemistry Forums => Citizen Chemist => Topic started by: Corbin on March 26, 2020, 09:37:00 AM

Title: Chemistry of Guitar
Post by: Corbin on March 26, 2020, 09:37:00 AM
Hey guys,

I have never posted on a forum before so excuse me if I don't exactly know what I'm doing.

I am making a project (online now) on the chemical composition of guitar strings. I know the materials, such as the phosphor bronze, the high carbon steel etc. (I'm not exactly well versed in chemistry terms) I was trying to find diagrams, or even like a formula for some of these composites? I apologize it's hard to ask for something when you don't know what you're asking for. I would greatly appreciate some help in figuring out what I am looking for, and getting like a diagram to put into this project.

Thank you for taking the time to read this.
Title: Re: Chemistry of Guitar
Post by: AWK on March 26, 2020, 09:48:23 AM
Search patents.
Title: Re: Chemistry of Guitar
Post by: billnotgatez on March 26, 2020, 03:03:55 PM
What were your results when you typed in GOOGLE

how guitar strings are made

Then let us know what you do not understand from the results
Title: Re: Chemistry of Guitar
Post by: Enthalpy on March 27, 2020, 11:15:29 AM
Hi fellow musician, welcome here,

are all those strings made of metal? On some instruments (harp, bowed strings...) the core is polyamide, catgut or some more recent material, spun with a metal wire, sometimes two.

Alloys have a "composition" rather than a "formula". Some alloy elements are miscible in any proportion, for instance Cu and Ni, so we couldn't give a chemical formula like CuNi2 like we do for H2O. Other elements do make compounds in fixed proportions, for instance Fe3C, and these compounds can precipitate in the alloy, but the crystals they form are dispersed in a matrix of different composition. Exceptionally, the matrix can have nearly-fixed proportions like TiAl, but then it dissolves alloying elements or contains precipitates, in variable amount.

All together, the composition of an alloy varies continuously, so we don't give a formula for it, with integer coefficients on the numbers of atoms, but a composition, with decimal proportions of the mass of the elements.

If you search the Web for "high carbon steel" or "phosphor bronze", some designations suggest a composition, like XC90 or 42CrMo4, while other don't. Each economic zone has (several) different systems of naming, and the alloys are not fully equivalent. When you know a designation, the manufacturer's data gives a range of alloy composition. Many "high carbon steel" and "phosphor bronze" alloys exist, and usually the string manufacturer doesn't tell which one he uses.

The processing history of the string is as important as its composition. Musical strings must be extremely resistant, because usually they shall propagate the sound faster than air does, and when the instrument doesn't need that, the string's core is overspun with metal wire so the core is extremely stressed nevertheless. For steel, 342m/s means 920MPa tensile stress, but 1.3*342m/s is better, and the string needs margins, so well over 2000MPa is desired. This is obtained by cold-drawing the wire extremely. The process was invented for music instruments, especially pianos, and later aeroplanes and other activities used the "piano wire" too.

One manufacturer here
guaranteed 2790MPa, wooooooow.  :o

My ramblings about music strings there
Title: Re: Chemistry of Guitar
Post by: Corribus on March 27, 2020, 11:34:22 AM
What about the most critical thing: the material affects the combination of overtone frequencies that contribute to the sounds of notes played!
Title: Re: Chemistry of Guitar
Post by: Corbin on March 27, 2020, 12:37:24 PM
Thank you guys so much for the *delete me* I have since finished my project genuinely with the help of all of you, exception 1 haha. I genuinely appreciate the time you guys took out of your day to answer, let alone read the post (billnotgatez didn't lol). Happy quarantine everyone.
Title: Re: Chemistry of Guitar
Post by: Enthalpy on April 01, 2020, 08:59:03 AM
What about the most critical thing: the material affects the combination of overtone frequencies that contribute to the sounds of notes played!

If only Mankind had working models about that! ::)

We still ignore to a high degree of accuracy what makes a string sound one way or an other. The same for winds and percussions, by the way. I've proposed two models (possibly the first numerically credible ones) about how the wall material influences the timbre and emission of a wind instrument, there

While I have some thoughts about string materials, their description will wait. What is sure: explanations based on flexural stiffness and inharmonicity have had some merit but are outrageously overstretched and misused meanwhile.

One difficulty about timbre perception is that musical sounds are not periodic and shall not be. Ol' Helmholtz botched that completely, and because scientists don't behave scientifically, we still suffer from his misconceptions a century later, and lost nearly a century of progress in that field. Ouch. But many thanks to Helmholtz for the Steinway pianos.


Since material scientists are present on this forum: we need better polymers as string materials please. Very simple physical properties: sound velocity sqrt (stress/density) must exceed the 342m/s in air by 1.3× plus a good safety and misuse factor (knots), which demands very strong or light materials. The material shall not dampen, which excludes most rope polymers. And it must stretch a lot elastically - linearly would be much appreciated, independently of temperature too. Fibres of meta-aramide maybe? Fibres of natural collagen?

The best strings, especially for harps, are made of sheep gut. Some sheaths of some part of the gut, carefully selected and processed by hand. Stretch-hardened nylon sounds badly, other polymers are worse up to now. If one makes a good polymer, he can sell it for tennis rackets too: only amateurs play on high-tech fibres, pros have catgut.

Same for pads at the note holes of woodwinds. Made of sheep gut or of fish skin for flutes, of leather for saxophones. Kangaroo leather is the latest improvement (called "roo-pad", easily remembered by French speakers too).

That's not an April's fool. Polymers as good as natural materials would be welcome in these applications.