Glossary · Case & Dial
Balance-cock jewel setting
The jewelled bearing mounted in the balance cock supporting the upper balance-staff pivot.
Explanation
The balance-cock jewel setting is the jewelled bearing in the balance cock supporting the balance staff's upper pivot, paired with the lower setting in the main plate. In shock-protected movements it sits in a spring-held assembly. Its condition — cracks, chips, correct endshake — directly affects amplitude and rate.