Myths and Misconceptions About Strings by Gene Fields

Reprinted from Ozark Steel Guitar Association Newsletter #19, January 1998. Used with permission.

Gene Fields was with Fender Music research for 23 years. 16 years in instruments research and 7 years with the string division covering everything from R & D Quality Control, machine and tool design, and purchasing of machinery.

I have been asked to write an article about strings. There are many myths and misconceptions concerning this subject. I would like to answer as many claims and questions as I can.

One of the things I treasured during the Fender years was their willingness to let me research extensively before finalizing the product. This included sending me to the source for information. I have visited many foundries including 3 core wire foundries and several cover wire foundries. I have been to and worked with engineers from Now Departure, Fafnir, and Barden Bearing Manufacturer, to research spindle design. I have been through the manufacturing area of at least half of the string manufacturers. I also worked with SIT Strings with some of their machines and machine design. This may sound like I am blowing my own horn and I guess I am, but it also establishes a right to speak on the subject.

There are many kinds of material available for string construction. I will not try to cover them all, only the ones most widely used. Core wire is the dominant factor in all string making. Core wire in the industry is not only wire to wind on, but all plain strings as well. Almost all cover wire is made from Swedish Mandolin Wire. Most of the raw material actually comes from Sweden, however, there is an American copy.

The raw material is usually supplied in large rolls of approximately 7/32 rod and fed through many sets of rollers before reaching its final diameter. As the pressure of these rollers work to harden the metal, it must be annealed periodically to keep it from becoming too brittle to work with. Almost all core wire is tin coated. the annealing and heat treating is the most critical part of the manufacturing process. If the wire is too soft, the twist will not hold. If the wire is too hard, it becomes brittle and will fracture during the twisting operation. The margin for error in heat treatment is very narrow. It is not unusual for soft or hard wire to get past quality control at the foundry or even the string company.

Most string companies will perform a break test. SIT String Co. and some other string companies perform break tests on every coil. When core wire is too soft, it will slip in the twist. This will usually happen slowly. The only clue the customer will have is a constant detuning, always dropping. This is a major problem to pedal guitars as well as guitars with tremolos.

As the margin for error is so narrow it is impossible to ship 100% perfect strings. Different companies have different ways to build in a safe guard against this problem. To the best of my knowledge SIT was the first to develop a method of locking the twist. This was the basis for starting the company SIT (Stay in Tune). Ernie Ball, Fender and others have been soldering the twist for years. I am sure there are other methods used that I am not aware of.

When the core wire is too hard, it will become brittle and break easy. The break will usually happen at the twist or at the key, usually during installation. Hard wire would make a better string except for the breakage. Some of this wire will get through in spite of the best efforts to guard against it. This is a major problem on the strings tuned to F# or higher. Every string manufacturer will have this problem periodically. If a customer should receive a group of strings from a particular manufacturer, he should not avoid this company forever. Try strings from a different production run. Sometimes this means changing companies temporarily.

Another problem arises when a ball end machine is set too tight. This will cause the string to kink and fracture at the end of the last twist. This will cause excessive breakage at the twist only. This problem is usually visible and should not be confused with brittle wire. If this happens too often with the same company, it should be avoided in the future.

Core wire for wound strings is another story. This wire is usually the same composition as the plain strings. Many different methods are used to keep windings from slipping. The most widely used, and in my opinion, far superior to any other method, is hex shaped wire. This wire is excellent because the cover locks on to the core wire at every corner of the hex. This wire is also tin coated. As this wire is so widely used, it covers anything we are concerned with for pedal guitars.

The reason for wound strings is simple, the larger the wire, the lower the frequency produced in a given diameter and scale length. To produce the lower notes, especially in the short scale of the pedal guitar, the wire would be so large and stiff it would not vibrate, to overcome this problem, a smaller core is used while the winding adds weight to make it respond to the lower frequencies while retaining its flexibility. The smaller the core wire for a given diameter, the greater the flexibility, however a careful balance must be reached. Core wire will usually vary from 1/3 to 1/2 of the total diameter of the string. This will vary with different gauges. This can also vary from one company to another. This is why it is sometimes necessary to retune the pedals when changing from one company to another on any given gauge

Cover wire comes in many different materials. bronze, phosphor bronze, silver plated copper, pure nickel, nickel plated steel, and stainless steel to name a few. For the most part, only three of these will enter the picture for use in pedal guitar strings. Pure nickel is the softest and easiest to wind. It is also the heaviest, making it respond better to low frequency. Nickel plated steel is more magnetic creating more out put per given diameter, a good choice if you prefer heavier bass response. Nickel plated steel is plated to 8% of total weight while still in the rod form, then rolled down to its diameter. Stainless steel is the hardest with more resistance to bending. It also does less detuning in the winding process. Creating a tighter winding and a brighter sound. Contrary to popular belief, some of the 40 series stainless steel have magnetic properties. This is the case with 430 stainless, normally used in strings. Stainless steel strings are very tough and are abrasive to stainless steel bars. If stainless strings are used, the bar should be hard chrome.

Cover wire is often deformed deliberately in the winding process to eliminate finger and bar noise. Flat wound strings were very popular in the past and are still used to a much lesser degree. This process made the smoothest string available but lost a lot of brightness. 430 stainless winding was used to regain some of the brightness. Another method is used by Fender and G.H.S. to achieve less finger and bar noise with much less loss of high frequency response. This method is called roller winding. The wire is fed between rollers and flattened to a much lesser degree in the winding process. This method produced less finger noise than round wound, but were much brighter than flat wound.S.I.T. string company has a new string called Silencers, that is flattened for less bar noise, but doesn't seem to have any loss of brightness.

Another factor in the brightness is the feed angle during the winding process. If the angle is too great the windings will spread and have gaps between the windings. This would be good if it could be controlled perfectly. If the spreads vary in width the string will note out by varying degrees directly related to the spreads. A perfect spread is almost impossible to control. The next best thing is to set the winding angle so the wire rubs lightly on itself while winding. If the angle is too shallow, the winding will try to climb on the previous winding causing roughness to the string. This will also affect the brightness as windings that are too tight decrease the flexibility which is a must for high frequency response.

The major factor in the life of a string is how fast the debris and corrosion builds up between the windings. When the openings fill up the string will go dead regardless of what winding material was used. Even though your hands feel clean and dry after playing even short while, the strings should be wiped with a fast drying solvent. Alcohol will do fine a long as it does not come off from behind the bar.

Even with the best of materials, plus locking the twist, there will still be stretching periods with any new strings. New strings will not form to the bridge and nut immediately. Before stretching in the strings, press all strings firmly on the playing side of the bridge and nut. This will help form the bend. Tune all the strings to pitch then pull up on each string 3 or 4 times, being careful not to break the high strings. Retune to pitch and repeat these steps until the strings stabilize.

During most of my years in the string division, I was responsible for only research and development of strings and machinery plus quality control. I had an excellent quality control supervisor working for me. This left me a lot of time to experiment and evaluate products. With all the time I have spent evaluating strings, from every company in the business at the time, I have come to the conclusion that there is no magic or perfect pedal guitar strings. There is no string that will stay in perfect tune all the time, there is no unbreakable strings, there is no pedal guitar that will not break strings. I am very proud of the GFI keyless pedal guitar. It has a lot of advantages, but it or any other keyless pedal guitar will not eliminate string breakage. It will decrease the breakage. As the overall strings are shorter, less bending is required at the changer.

To understand this one must understand the nature of the material. We all know that when a piece of metal is bent enough times it will break. This is commonly known as metal fatigue. for the answer to the pedal guitar problem we must understand metal fatigue. Bending a piece of metal one time will make it harder. This is hardly measurable. Bend it enough times and it will get so hard it will become brittle and break. This is what happens at the changer every time the pedal is pushed. When the string is bent enough times it will become brittle and break, in spite of the fact that there is a keyless tuner on one end or a solder or locked twist on the other. A short or long twist makes no difference as long as it does not reach the bending point.

Most reputable string companies make good products. This article is not intended to endorse or criticize any particular string company.

There is a new string on the market with a colbalt winding. I would guess it is 8% cobalt is this is a common material in the cutting tool industry I will be testing them in the very near future. At this point I do not know enough about them to comment.

I realize this article got rather lengthy but I felt it necessary to understand the material in order to cope with the problems.

Gene Fields

GFI Musical Products