====== Screw balance ======

{{wst>image_l|Schraubenunruh|**Screw balance** \\ © [[A. Lange & Söhne]]}}

A **screw balance** is a [[balance wheel]] that has adjustable [[regulation screws]] and tiny washers along its rim.

These screws previously performed the following functions 

  * A possibly existent unbalance of the balance can be compensated by the screws. 
  * The oscillation frequency of the balance can be changed.

Both measures are intended to improve the accuracy of the watch.

Screw balances can be found only in high-grade watch [[movement]]s. This applies to the past and the present. From today's perspective a screw balance brings no more advantages due to extremely low production tolerances with usual balances. However, some watch movements are still manufactured with screw balances, as they are a feature of high-quality watch movements, and also nice to look at.


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