Reeds for jew's harps
One of the main questions arising in the process of repairing of a broken or creating a new jew's harp is choice of material for the reed. This small note contains information taken from conversations with blacksmiths of jew's harp, from different publications, and also from the author's own small experience.
Steel can be treated by heat to give it different properties of hardness and softness. This depends on the amount of carbon in the steel (only high carbon steel can be hardened and tempered). The blacksmiths usually use instrumental steel heat-treated to the necessary elasticity. The industrial heat treatment of steel is a very complex and science. More simply speaking heat treatment is the following process. To harden the metal it is heated till its orange hot (till certain high temperature 800 to 900 °С). Then the metal is quenched in clean water or cold оil. As a result steel gets extraordinary strength, but becomes brittle and fragile. This means it is likely to break if put under pressure. The following process is called tempering of the steel. That means that heated till less temperature (200-500°С) steel is allowed to cool slowly in the air. Mechanical behavior of metals change by this reason, steel becomes less strong. The tempering process has taken most of the brittleness from the steel. Allowing you not have the reed crack and shatter. Crashworthiness and resource of the reed increase because of it. The qualitative heat processing in reality is more difficult then it is described here. And it demands a lot of expensive special equipment and experience. That is why a lot of blacksmiths do not do it by themselves. They choose suitable heat-treated steel things and do reeds of them.
Working with the reed it is necessary to sustain its characteristics unchanged. When you cut off a strip by a diamond disk or a corundum wheel you should cool the blank. We get the necessary reed form with the use of a grinding machine, also constantly chilling it in cold water. This segment can be chilled in the air smoothly. It is obligatory to heat only the place of ringing. For this reason the butt of the reed is to be лучше enveloped in a wet duster. The loop of the reed should be made up this way.
Some Yakut blacksmiths for making of reeds of jew's harps more often use a two man saw blade. The oldster blacksmith Borisov P.М. considers that mechanical properties of this steel are very close to optimal ones for Yakut traditions. Only sometimes making special jew's harps he anneals steel and heats it in a different way.
Norwegian blacksmiths (Folke Nesland, Bjorgulv Straume) use industrial saws of stainless steel for meat and bones (see picture). The reed is cut by an intercooled angle grinder. Information from source :
Other Norwegian blacksmiths Jakob Lavoll makes reeds of watch spring .
Soviet pad-saws usually were made of tool steels U7, U7А, U8, U8А and were heat treated till hardness of the web 42...52 HRCэ. Soviet metal school lines were made of the same steel and were heat treated till hardness 40...54 HRC.
It is possible to harden steel not only by heat treatment process but also with the use of the so called peening process. A cold steel billet of the reed is processed by hammer blows. Its hardness increases of it. By the way the same method is used to harden brass billets for Vietnamese Dan Моi.
Source of information:
1. THE PARNU TYPE OF WEDGED JEW'S HARP
Quest for Historical Sources and Manufacturing Techniques
Telemark University College
Faculty of Arts, Folk Culture and Teacher Education
Institute of Folk Culture, Rauland
2. Jew's harp traditions in Norway By Lars Willadsen
3. Линейки измерительные металлические ГОСТ 427-75
Ножовки по дереву ГОСТ 26215-84
© Vladimir Markov 2009, this article translated by Natalia Ivanitsa