Keeping guitar strings in tune

A durable stainless steel string that doesn't go out of tune has given Sandvik a way into the music industry.

Traditionally, most strings in musical instruments are made of carbon steel, but sweaty fingers degrade the material, causing the instrument to lose tone, and eventually the carbon steel will rust. Demanding musicians often purchase strings coated with a polymer to prevent corrosion. Many professional guitarists also change strings every time they play.

"With our string material, no coating is necessary," says Phil Etheridge, Application Specialist at Sandvik Wire. "Our researchers have developed a stainless steel version that sounds really good and has a lovely feel, with a shiny soft surface."

Etheridge is a guitarist himself and has worked with the market introduction of Sandvik's string material, called Audioflex, since its beginning three or four years ago. A comprehensive test was previously carried out with a different steel grade, which turned out to be too fragile.

"The challenge is to get enough strength in the material and, at the same time, retain its ductility," Etheridge says, explaining that steel with high ductility can be strongly deformed without breaking.

Soft and flexible, yet strong, were the basic demands set for the new stainless steel string.

A bright future for Audioflex

Tests have shown that Audioflex lasts longer than normal strings made of carbon steel. After two professional violinists gave their recommendations, two well-regarded manufacturers in Germany and Sweden decided to mass-produce stainless steel strings using Sandvik material. Both companies specialize in classic string instruments such as the violin and the cello, and Etheridge says production volumes are small to start with.

The goal is to get a foot in the door of the large mass producers of guitar strings.

"There is interest, without a doubt," Etheridge says. "One of the world's leading string producers in the U.S. recently bought a few pounds of our stainless steel material to start test-manufacturing strings for violins and hopefully also for acoustic guitars. If they continue with mass production, the future looks bright for Audioflex."


Sandvik's stainless steel wire Audioflex is most suitable for the thinner strings for acoustic guitars and violins - the E, B and G strings for guitars and the E string for violins. The other strings are often wound.

The material is magnetic. After some modification it's suitable for use in electric guitars, where an electromagnetic microphone takes up the vibrations of the strings and translates them into electrical signals.