Hole jewel replacement

The watch movements have some bearing jewels.
The main reasons are for:

• To move wheels smoothly without friction and transmit power efficiently.
• To prevent wear of wheel’s pivots.

If a hole jewel has chip or crack, the pivot will make damage.

The jewel has chip around the hole.

The chipped jewel has been taken out.

Reaming the hole for a replacement hole jewel.
The most important thing for the job is keep the center.

The new hole jewel has been replaced.

Completed!