The Cylindrical Pivot and Jewel
The cylindrical pivot (1) has the advantage of simplicity, robustness, and low cost. The friction of the cylindrical pivot is relatively high compared to the two-jewel arrangement used with the
conical pivot. This friction results from the relatively thick jewel hole (2) and the pivot shoulder rubbing on the backside of the jewel (3) on the bottom pivot.
The cylindrical pivot is used for the mainspring barrel and gear train of the watch. The balance wheel usually uses a conical pivot, as does the escape wheel in many finer watches.
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