THE UNIMPORTANCE OF STRING GAUGE TO TENSION
This edition of String Tips is about something we seem to get questions about on a somewhat
regular basis. The questions often take the form of "what gauge are your ..... strings" or "what
tension are your ..... strings". The idea is that this information can be used to compare one set
of strings, in this case ours, with strings someone may already be familiar with. In other words
to know what to expect from ours. Obviously, this sort of information might be extremely
useful in purchasing strings for your Ukulele from anyone.
So how then, can you avoid the common "shot in the dark" process of blindly buying one
string set after another - hoping against hope that the next set will be "the one"? How can a
knowledge of string gauges and tension be used to make your buying experience more
certain?
In short, it can't. Or to state it another way, that sort of knowledge is practically useless.
Actually "useless" is being kind. This sort of data almost always just confuses matters and
makes the buying experience worse.
There is almost no application for this sort of thing. Diameter and tension could indeed figure
into the calculation of a set of strings for a new scale or tuning, based on a specific material
whose properties you already know and which you know will remain constant throughout all
diameters. But this type of reference was used for string material that came into being close to
a century ago; it is useless for well over 90% of all material used for strings on the Ukulele
today.
****************************
Let's start with “tension” and show where that leads. The problem with tension data as it's
currently presented, is that it doesn't correspond to the common understanding of the word.
When people speak of string tension - this includes us - the common meaning is that we're
talking about how tight or loose a set of strings will feel. Tension data, however, tells you
about strings before you feel them. It's a measure of the pull exerted by a string or set of strings
when they are at rest. That's not your main concern, however, because it doesn't tell you how
they'll feel or how they’ll play. It's useless to you because that data ignores flexibility.
The best example of this is a wound steel string. By this, I mean a true steel string, an all steel
winding, not the common wound Classical string, where metal is spun over a softer core. If
you think about it, why would you wind a steel string to begin with? Lighter gauge plain steel
strings are smoother, and thus noise free under hand. Why not just continue the practice of
using a plain steel "rod" so to speak, as is used in those thinner gauges, when you need a
heavier string for a low note. It's because of the need for some flexibility.
At some point, the "steel rod" gets thick enough to where it just doesn't function as a musical
instrument string. You'd bring it up to tension, and then try to strum it, and you'd feel like
you'd broken your finger. Not only that, but the tension of such a string would actually have
to be very low in order to keep that stiff, inflexible steel rod from tearing off the bridge. By
contrast a spiral, or "round wound" steel string having the same weight per inch could actually
be brought up to a higher tension and yet still feel much easier to play. It is simply more
flexible.
While this situation may be easier to conceptualize with wound versus plain steel, the example
can be applied to any two types of string material. At one time we had a unique type of flat
wound string - one with a construction that allowed it to work on a classical braced
instrument. But those strings gave less flexibility than our polished round wound, or “ground
wound” strings. Those flat wound strings were found in the Linear sets where we classified
them as “Heavy Medium Gauge”. But - - they actually had less tension in the “scientific - at
rest” measurement than the ground wound strings we also called “Heavy Medium”. When
the the two were tuned to the same pitch, however, the lack of flexibility in the flatwound
strings meant they had the same “feel” as the Heavy Medium ground wounds. If we simply
published tension data instead of our “classification by feel”, then those who rely on tension
data to make their string choices might have thought the flatwound set, because of lower
tension, would have had a more relaxed feel than Heavy Medium ground wounds. And they
would have been dead wrong.
These kinds of examples are useful with various types of plain strings as well. A fluorocarbon
string, for example, is typically stiffer than a nylon. So, up to a certain point, a typical all
fluorocarbon string set could actually have a slightly lower tension than a typical all nylon set,
and yet feel more difficult to play. Hopefully these examples serve to illustrate the futility of
relying on tension data to make an informed decision on string choices. It can only guide you
when comparing strings of exactly the same formula, so you have the same sort of flexibility.
And “exactly” doesn’t actually mean what you might assume either. We’ll talk about that
later.
****************************
But now, when it comes to relying on string diameter to help you in your choices, you run up
against another missing element. In this case it is density. A simple example of this would be
to compare a wound classical string and plain string, each of a gauge that would allow them to
be tuned to the same pitch at the same tension. The wound string would be substantially
thinner, because it is denser, or heavier. Another way to look at this would be that if instead,
the strings were of the same diameter. In that instance the wound string, per inch, would
weigh more and would need to be tuned to a lower pitch to be at the same tension (or feel) as
the lighter density plain string.
These same considerations also apply when comparing wound strings to each other, or plain
strings to each other. One wound string may use a heavier metal for its winding -- with others,
the proportion of metal to core (often silk nylon) will vary. With plain strings, you can again
use the example of a typical fluorocarbon versus a typical nylon. The fluorocarbon is denser, so
with strings tuned to the same pitch -- same scale -- same tension -- the fluorocarbon is
generally thinner.
We say "generally", because as we stated earlier, for diameter to be meaningful information
you need to know the specific characteristics of the particular string. Just knowing that's it's a
fluoro or a nylon is not enough. There are hundreds of fluoro formulae -- thousands of nylon
varieties. They all vary in density, and the result is that in some instances, those materials have
started to overlap in how they both sound and perform as musical instrument strings.
To give a specific example from our own strings, we had one very popular all plain set; It was
an all fluoro set, but as is always the case with us, it was made of mixed materials; in this
particular case, the set used four different types of fluoro. This practice, when done properly,
yields better balance in sound, feel and playing diameter. The outside strings (this was an
Ukulele reentrant set) were of the exact same diameter and they were exactly the same in
tension (or feel) as well. This was in spite of the fact that they were tuned a full note apart. The
moral is, even when comparing a "type" of string, such as fluorocarbon, you can end up a full
step off (or more) in the tension you'd want by judging a string on diameter.
****************************
Some folks will attempt to get very scientific with this sort of data. There are “string tension
calculators” that supposedly will help you choose strings of a proper tension. Can this sort of
tool have an application in at least a limited circumstance? Yes, but the limits are a lot more
severe than you might imagine.
Most of what you will find will be “general string calculators”. So in those instances, let’s say
you’re going to to restrict your “scientific calculations” to a specific type of string: wound
(classical), fluorocarbon or nylon. But as mentioned earlier, wound strings will differ, even
when the metal wrapping is the same. The thickness of that wrapping may change, the type
and thickness of the core may change, and the relation of wrapping to core may change as
well, even within a set of strings called “Silver Wound”, for example. Since string calculators
work with a specified “weight per volume”, then if the weight/volume of one wound string
within a set is different from the next, as is often the case, then using a single density for your
calculations will only serve to mislead; trying to weigh each string diameter and then use a
variety of densities defeats the entire purpose of the exercise in the first place.
And the same situation occurs with practically all modern plain string formulations as well.
What happens with the various types of fluorocarbon or the modern varieties of nylon is that
the weight/volume of those strings also might change as the diameters increase. The reasons
are twofold.
First, these new materials start out harder than the original Dupont nylon formula in the
smaller gauges. As they increase in size this gives rise to two problems. First, thicker strings
at some point reach the stage where they aren’t flexible enough to knot. It’s a similar situation
to that previous wound steel string example. This is not just a problem for tying to the tuners
or bridge of your Ukulele, but the majority of fluorocarbon goes to the medical or fishing
industries, and the ability to knot the material is critical there as well. Therefore, various types
of additives are put into the formulation to increase flexibility as the diameters increase. These
may or may not increase or decrease the weight/volume, but they always make the string more
flexible, giving it a different feel than the harder, smaller diameter compositions will have.
The other quality it always imparts is a duller sound than the harder, “purer” material in the
thinner diameter strings. So string thickness is only a part of why modern plain strings
become warmer as the gauges increase. Formulation changes as the gauges increase may (or
may not) effect weight/volume, but will always effect flexibility and sound.
So why not simply keep the purer formula the same for musical instrument strings? There
might be solutions to overcome the knotting difficulties on musical instruments. Strings like
that could be a wonderful thing in musical applications and would substantially increase the
usable range of plain strings. But there is an additional problem with going that route. Plastic
material is extruded in specified diameters to manufacture strings. That extrusion process has
its limitations as well. When you combine a dense formulation with a thick gauge you begin
to lose consistency in the extruded diameter. That also means you lose consistent intonation.
We’ve run tests trying this sort of thing, and the results are not pretty.
String manufacturers all have their own take on where in the extrusion process to change the
purity of their formulae. It’s based on how hard they start out with the thinner strings and
where they feel they need to change their formulae in order to keep extruded diameters
consistent and have a usable flexibility. Some have an almost constant change, but most work
with “cut-off points”. In other words, a certain purity is maintained up to a certain gauge and
then it will be altered for another few gauges until it changes again. And every manufacturer
will do this in a somewhat different form. It shows that even in the modern world of plastic
strings, their formulation ultimately still contains a significant amount of subjective
judgement, or might we say “Art” as opposed to pure science.
So in short, these general string calculators are another waste of time with most modern
material. There is one specific string calculator that actually may have some very limited use,
however, and that is the online application from D’Addario. You are given two options in the
beginning: to either choose to have the application base its calculations on D’Addario material
or not. If you choose not to do so, then it is no different in its limitations than any other
general string calculator. Not having tested it with the option to use D’Addario based values,
one would simply assume that they know their own string weights, when those weights
change as the gauges increase, and would then not used fixed values in those calculations.
Just realize they would only apply to D’Addario material, and you would need some
experience with one of their specific formulations to serve as your reference to compare with
another D’Addario formula.
****************************
At this point you may be asking yourself why most reputable string companies still publish
this sort of data? Doesn't that indicate it has some utility? We mentioned D’Addario’s
practice, though it’s doubtful there are many who understand the limitations of that
application. With others, I have a feeling the continuation of this practice comes from two
main sources. First, this data is still very useful to steel string players. With plain steel strings,
you are essentially comparing material of equal density and feel. With the wound strings,
there can be some slight variation, but that variation is not nearly as extreme as what is found
with wound classical strings.
Then, there was a substantial period in the mid 20
th
century where almost everyone used the
original Dupont formula nylon for their plain classical strings. This is a very soft, flexible
material to begin with, and since this sort of manufacture was then in its infancy, the modern
practice of changing the formulation from “stiffer to more flexible” as the gauges increased
didn’t exist at that time. It’s simply a more sophisticated manufacturing technique that didn’t
become common until decades later. But the original formula nylon developed a following.
People were used to the sound, used to the feel, and it has retained a certain popularity to this
very day. Since being, in a sense, a “primitive” form of synthetic string, the density actually
does remain constant with old formula nylon. So as with steel, tension data still has meaning
in this case, and familiarity with the flexibility of the material gives at least some indication of
what changes to expect in feel when changing tension.
People coming from the steel string world, or used to the older nylon treble material got used
to using this data; it is probably just easier today for string companies to continue to provide
that data rather than explain why it no longer works well with their newer formulations.
****************************
So as you can see, tension and diameter data is simply not useful in most instances. And for
string sets like ours this is especially true. In mixing materials, we have what might look like
an odd set of diameters compared to single material sets. By selecting denser formulae for
deeper notes, those strings are usually not as thick as typical, and by the same token, strings
for higher notes often have less dense material and slightly heavier gauges than is customary,
at least in relation to the heavier strings. This is of course by design, as it also gives more
uniform diameters, producing a better feel, and more uniformity in sound as well, yielding
clearer bass notes and smoother trebles. But those accustomed to judging strings by their
diameter would likely just get confused. So by not publishing data which is misleading to
begin with, we try to help these folks avoid totally misguided pursuits.
But unfortunately, popular mythology has created a sizeable number of people who have been
led down that “diameter/tension” path. Traditional guitar and Ukulele string set formulation
("cheap" sets, as we refer to them) are made from as few materials as possible. With plain sets,
that would be one material. Looking at an all plain set as an example, the "cheap" sets have a
wider variation, both in tension and diameter than a comparable set of ours would have. A
typical cheap reentrant set, for example, would have a 3
rd
string that's thicker in relation to the
outside strings than one of our sets would have. The tension on most cheap 3
rd
strings would
be lower than ours, and the tension on the outside strings would be higher.
This is done to try to balance the tone. With only one material, the thin strings are much
brighter than the thick strings, so the thick string is made as thin (floppy) as possible to keep
the tone as bright as possible, and the outside strings are given extra thickness / tension to try
to muffle their brightness a bit.
Our way of doing things, mixing material of varying densities, is how many orchestral string
sets are put together. Sometimes people buy a variety of individual string types -- on occasion
costing as much as $100 per string - until they find the balance, in terms of feel and tone that
give them what they want. And even if you look at the strings in many companies stock
offerings, you’ll see that they aren’t all of the same material. Also note that tension data is not
common with orchestral sets either. Ukulele players tend to think that guitarists are more
sophisticated and have a very unfortunate tendency to follow “all things guitar”. But
compared to orchestral players guitarists are a very backward lot. You don’t have Violinists,
for example, trying to “calculate tensions” or looking at string diameters. They are focused on
the primary elements: sound and feel; elements which are quite apart from the out-dated
science still sometimes used by classical guitarists, and often by extension Ukulelists.
****************************
So to sum up, don't rely on tension or diameter when comparing the string offerings from
different companies. To some extent, buying string sets will always be that "shot in the dark".
Unless someone comes up with a way to add density and flexibility data to diameter and
tension data, and do it in a way that buyers could quickly grasp, trial and error will be the only
true way to get to the best sound and feel for you and your instrument.
But we feel we've reduced that process substantially. Our tension ratings are subjective. But
having one of our sets gives you a frame of reference. And if you don't get exactly what you
were looking for the first time around, at least the next set is no longer truly that shot in the
dark. You can see where to go for a firmer or lighter feel, a brighter or softer sound. And you
get better balanced tone and tension in the bargain.
****************************
One final note: there are some who will use diameters, not to try to estimate playability or
tension, but to decide whether or not new strings might cause a problem with their set-up.
This is a classic case of putting the cart before the horse.
The "bones" on a plucked stringed instrument are removable precisely so they can be easily
adjusted. This feature is an essential part of the design of a stringed instrument. So play new
strings without regard to intonation or buzzing. Keep trying until you find the sound and feel
you're looking for -- then make the adjustments your instrument was designed to allow for.
You never want to let your bones dictate your strings. Your strings, after all, are the prime
element in your quality of sound.