Guitar String Gauges – Tension, Corrosion & Replacing Strings

In our introductory article about the guitar strings, we had discussed about gut, nylon & steel strings along with details of the winding used on these strings. In this article, we will discuss about the following topics:

• string gauge, categorization of strings based on gauge and the tension,
• issues faced by players due to ageing of strings
• when to replace the strings
• making your own string set,

Guitar String Gauges & Tension

String gauge is defined as the thickness or diameter of the string in “thousandth of an inch”. String Gauge of “10” means that the diameter of the string in inches is 10/1000 = 0.010 inches. Packs of guitar strings are usually referred to by the gauge or diameter of their thinnest string.

Heavier gauge means thicker string and more tension exerted by it. With higher tension, you also need to apply more force to press the string against the fret.  Heavier strings produce and transmit more energy to the top of the guitar, which means much louder sound. Lighter gauges are easier for beginners as they require much less finger strength and more accuracy.

The string gauge is measured by micrometer having measurement accuracy to a thousandth of an inch. These instruments are fairly expensive.

The sets of guitar strings are categorized by the string industry in the following categories:

• Ultra-light
• Super-light
• Extra-light
• Light
• Medium
• Heavy

Actual gauge of a particular string in a category can vary slightly between different brands, depending on the guitar or music being targeted. Let us look at each of these categories in some detail. 

Ultra-light and Super-light.

These strings sets have diameter of 0.008 and 0.009 inches respectively for the smallest or the 1^st string.

• These are used mainly for electric guitars, requiring lot of string bending.
• These strings are not able to impart sufficient energy to the top of acoustic guitar; hence the sound is not more than a whisper. Thus, it is not very meaningful to use them till you have magnetic pickup to detect string vibrations.
• Transducer pickups, that work on body vibrations are not useful on acoustic guitars with these strings.

Extra Light

These sets start at 0.010 and 0.011 and are good for delicate guitars.

• They are suitable for blues and contemporary styles requiring string bending and vibrato.
• For beginners, the set is good to practice for few months, till you are able to apply more finger pressure required by thicker strings.

Light Gauge

Starting diameter for this set is 0.012.

• These sets are good for long term and provide best balance between volume, tone, ease of playing, sensitivity to bending and vibrato.
• They are suitable for flatpicking, fingerpicking or playing by bare fingers.

Medium Gauge

Medium gauge strings start at 0.013. The main features are

• These strings are used on instruments, sturdy enough to bear string tension. The instruments should also be capable to diffuse the energy transmitted by the strings.
• Guitars with medium sized strings are played with flatpicks or fingerpicks. These strings are very good for fast playing with flatpicks, as the picks come off quickly from the string due to more tension. Lighter strings would bend under the pick pressure while playing fast.  
• Usually string bending is not done while playing because these are quite hard and painful to bend.
• The strings are used on dreadnoughts and jumbo sized guitars.
• These are favoured by bluegrass musicians & heavy strummers.
• You will not get very good results if you use these strings on heavy built laminated top guitars.

Heavy Gauge

The diameter of the 1^st string of the heaviest gauge is 0.014.

• Use of these strings on most new guitars will make the warranty void, unless the guitars are specifically designed for them.
• They are used on big sized acoustic archtop rhythm guitars. These instruments require huge energy to be transmitted to their top to perform.
• Most flattop guitars are not suitable for these strings.
• Due to their limited use, these strings are not very common and easy to find.

Compound Strings

• The Compound Strings have string tension comparable to those of extra light strings.
• Their sound is warmer and less brilliant.
• Gauges for these strings differ from brand to brand.

String Gauges for Different Genres

Expert musicians are able to use gauge of their choice for any genre. For less experienced players, there are general guidelines linking gauges to different musical styles.

Thin Strings

• Fingerpicking: Styles like folk and country music require fingerpicking. Thinner strings are better suited for clarity and speed on fingerpicking.
• String Bending: Thinner strings are easier to bend and hence suitable for Blues style. Some guitarists use thicker strings for Blues to get warm tone and more sustain.
• Fast Playing: Thin gauge is ideal for styles like Jazz, which require fast playing and more advanced techniques, because of much lower effort required in fretting.
• Higher middle and treble frequencies required: Lighter strings have sounds that are more focused in higher middle and treble frequency ranges. Music styles like pop require more representations from these ranges.  

Medium and Hybrid Strings

Medium strings are suitable for almost every genres.

Hybrid or mixed strings set types can be “Heavy top / Light bottom” string set, which will be discussed in our next section. They are not specifically made for any genre of music but add versatility in playing.

Thick Strings.

• Tuning from drop C and beyond: Thick gauges suit tuning from drop C or beyond. Combination of lower tuning and higher string gauge gives dark and phatter. Hence these are preferred for metal and heavy metal genres.
• More Volume, resonance and warmth:  These are the key requirements for acoustic guitars, which are provided by thicker strings. As there is very less or no requirements to bend strings here, higher string tensions can be tolerated.

As stated above, these are only guidelines and not rule.

Typical String Gauges and Tension

In the table below, the gauges of different strings in a set is presented along with approximate total tension. The values shown are the most common ones or average values. Exact values may vary slightly between different brands. This table is prepared for normal long scale guitar with 25.4 inches. The values for tension are marginally lower for short scale guitar that comes with 24.9 inches.

Tensions in the Nylon strings are much lower and usually in the range of 75lbs. On twelve string guitars, it is in the range of 205 to 250 pounds for different scales and gauge sets.

In modern times the string manufacturers have started to clearly discriminate between electric and acoustic guitars. In this case, the extra light string set for electric guitars might be different from extra light for acoustic guitars.

Some guitarists just call them “Thirteen to Fifty Six” string set using the gauge of first and the last string. Some even go one step further and just call them “Thirteens”.

It is becoming increasingly common to use mixed string sets to get a particular type or feel of sound or to suit some particular guitar. Let us see some examples for these type of sets:

• “Heavy top / Light bottom” set – Consider a string set comprised of “light” strings. If we replace the low strings in this set with corresponding medium gauge strings and high strings with extra light ones, we will get  “Heavy top / Light bottom” set. The purpose is to punch out low notes without making high notes very strong.
• Another popular mixed configuration is to have medium gauge strings on 1, 2 and 6 and light gauge strings for 3, 4 and 5. Tension of individual strings feel more even on such string sets, while playing.

String deposits and Corrosion

Continuous pressing of strings against frets, metal fatigue, corrosion and dirt are some of the factors which cause the string to deteriorate over time. If you are little vigilant and carry out regular maintenance, you can avoid these breakages. Let us look at some of these phenomenon

• Wound strings have maximum wear at the points where it is pressed at frets.
• Unwound strings lose their metal and become thinner when rubbed against frets.
• Tension in the string leads to change in molecular structure over time, leading to metal fatigue.
• Ambient Humidity leads to oxidation. The corrosion of string can be further accelerated in presence of acid from the perspiration and airborne impurities.
• The string gets coated with finger oils, dirt, residue from your fingers like dead skin etc.

All these factors lead to uneven distribution of mass along the string length and erratic intonation. It is recommended to

• Clean your hands before playing .
• Wipe the neck and stings with a clean cloth after playing.
• Use some string cleaners, which are able to penetrate the gaps and crevices in the winding and clean it of all types of deposits mentioned above.

String Breakage.

String breakages can be really frustrating if they happen during a live performance. They can break when they are struck too hard, due to flaw in the winding or simply because of age. But it is possible to minimize the breakages by carefully observing the breakage point and  analyzing the reason.

• Breakages at Bridge or Saddle – Saddle might have corroded or got slotted due to wear. The burred or improper shaped saddle can affect tuning and cause breakage. It is recommended to get this repaired by some professional unless you are very experienced. Improper filing can further aggravate the problem instead of solving.
• Breakages at Nut – The reason can be accumulation of dirt in the nut slot or wearing of the nut particularly for the heavier strings. This can lead to binding and increased string tension between nut and tuners. It is important to ensure smoothness of the nut slots. Make regular use of nut lubricant and ensure proper cleaning while replacing the strings. As with saddle, take help from experienced technicians if wear is there, necessitating filing to be done.
• Tuning Pegs – Burred edges inside the tuning posts and dust accumulation are the causes. You can make use of thick old wound strings and move it in circular motion through the string holes to smooth out any existing burrs.
• Frets – Burred frets can damage the string. It can be easily smoothed out with a sandpaper.
• Use of incorrect strings – If you want to use custom set of strings, make sure the string is subjected to the tension which is well below their design value.
• Picks – Heavier picks cause more wear on thinner strings. The situation is further aggravated if the pick has any sharp edge due to wear.

When to replace guitar string

By now, you have understood the mechanisms that cause wear and corrosion in guitar strings, leading to their breakages. Once a string breaks in the string set, it is recommended to replace the entire string set, unless the set is completely new. This will keep the strings in sound balance, and you don’t have to keep record of individual string replacement.

The frequency of replacement of strings depends on many factors such as

• Hours of daily practice or play
• How aggressively you pick
• How heavy your grip is on your fretting hand
• Is the ambient environment humid or contains smoke, like in clubs.
• Amount of sweat generated by your body and amount of acid contained in it.
• Amount of dead tissues deposited by your body on strings.
• The kind of strings you use

Based on answer to these questions, strings can last for many months for some players. While others with unfavorable body chemistry or hard playing styles may require replacing them in one or two months. Some serious players replace them every time they go for a performance or recording.

We recommend you pay close attention to your guitar strings and observe the following telltale signs giving you a clear message to replace the strings.

• Strings do not remain in tune: Tuning problems are more common in brand new or old strings. In most cases, the tuning issues will be because of deterioration of strings with age due to issues discussed above. In rare cases these can arise from bad tuners, warped neck etc. Just eliminate these factors before going for replacement of strings
• Guitar sound dull: If you have to play hard to get lively sound out of your strings, it is a clear indication that strings need replacement.
• Discoloration of guitar strings: Discoloration happens due to corrosion and deposits. If you see dull grey color on Nickel and Steel strings or dark brown color on Bronze strings, it is a sign that strings have passed their useful life and are ready to be replaced.
• Accumulation of dirt: If discoloration is not yet visible, but on sliding your finger, the surface does not feel smooth and slippery, it is most likely that dirt has accumulated over the strings. These will also impede you quick movement around the fretboard.
• Strings feel stiff: If the strings no longer feel flexible or bendable, it means that corrosion has started on your strings and will require replacement in near future.
• Fraying of windings with worn spots: Look out for visual signs of damage or wear and tear on the windings.

If you are not constrained for budget and are a learner or amateur player, it is recommended to replace the strings at least every three to four months. This period can be six months, if you clean your guitar strings regularly with string cleaners and conditioners and none of the above signs are visible.   

Making Your Own String Set

If you do not like any one of the prepackaged string sets available in the market or want to experiment, you can purchase single strings and make a custom string set. Other cheaper alternative is to buy complete standard set and replace one or two individual strings of your choice.

Electric guitarists are more into this type of experimentation. This is due to the simple fact that in case of ultra and super light strings, change in unit gauge has more pronounced effect than acoustic guitars. They try various string compositions, gauges and brands to find a combination which is best for their fingers and style of playing.

Take care that you do not mix grossly disproportionate strings. This combination will neither feel nor sound balanced together.

Change in gauge may require adjustment in string height at the bridge saddle, neck and nut.