Piano string making is an art in itself not to be confused with the works of a piano restorer. Piano strings are made almost exclusively by artisan string makers and their work is precise and skilled. Continue reading to find out more about more about how piano strings are made and their importance in modern pianos.
Treble Strings
Piano strings have developed over time to become more efficient and resonant. The piano has two different types of strings which are split in to the treble and bass sections. The treble strings are made purely of steel in different densities to create the best tone and pitch of note. To avoid impurities and false beats - wobbles - in the purity of the note, the quality of the steel used is very important. The same is true of the way in which the piano is strung, although that is a topic for another blog post. Some of the best quality piano strings are generally considered to be Roslau or Pitthan which are both drawn as purely as possible and have the greatest breaking strain.
Importantly, steel piano strings are bought from a supplier in large coils which can be put in a tin and used as necessary depending on the diameter needed. When changing a treble string it is important to replace the existing string with one of the same diameter for the correct tone and pitch. Any competent piano technician can do this easily in the home.
Bass Strings
Unlike treble strings which come in large pre made coils of differing diameter; copper bass strings are made to order by a specialist string maker. This is because copper bass strings are made to fit the exact piano depending on the size of the instrument, type of frame and stringing pattern. In order to replace a broken bass string with a new alternative, measurements or a rubbing must be taken and sent off to a string maker to create an exact copy. It is imperative that these measurements/rubbing are as accurate as possible as any small deviation can lead to an incorrectly made string.
Unlike the treble strings which are made just of steel, the bass strings are copper wound meaning that the steel inner core has copper wound around it at great tension. Over time it was found that in keeping the bass notes pure steel the density and length of that steel would have to be so great to create the right pitch, that the piano would be unrealistically large to accommodate them, and the note would have poor tone and sound production even so. In winding copper tightly around the steel core, the needed density was created without the negative effects of pure steel.
In making piano bass strings there are several variations. To create the lowest bass strings the copper is often double or triple wound - that is, layered on top of each other - to create the correct pitch and tone. The ends can be finished in different ways although the important thing is that the copper is finished securely so that it doesn't start to unwind, which would create buzzing in the string. Equally the bottom end of the string, which attaches to the piano frame via a hitch pin, can be finished in different ways according to style. Again these "eyes" which hold the string to the hitch pin are a matter of style; as long as the eye is made to minimum standards the important thing is that it holds to the hitch pin correctly.
It is possible to buy what are called hexacore bass strings, which are premade "off the shelf versions" which can be cut down to approximate size. These are however not a long term replacement for proper bass strings as they will never have the exact diameter and pitch/tone potential as a custom made string. A hexacore has a hexagon steel inner wire which prevents the copper from unwinding when it is cut to the approximate size needed for that particular replacement. Again, this hexagonal core will mean that it sounds different to the standard round core strings next to it.
In this video you can see how copper bass strings are made from receiving a paper rubbing of the strings all the way through to the finished product. We can not recommend it highly enough for gaining a basic understanding of piano bass string making.
We hope that this blog on How Are Piano Strings Made? has helped you gain an understanding in to this fascinating skill and appreciate it's importance in beautiful sound production. Please remember that this blog is aimed at the wider public not a detailed instruction or education for professionals. Please see the links below for sources to buy piano wire and bass strings.
Piano Strings Barney Unwin String Maker
https://www.fletcher-newman.co.uk/ Roslau strings
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