I have a 571 BWR that has a bent upper balance pivot (can change, no problem) and a damaged upper hole jewel. What has me a little disturbed is the upper hole jewel...

As you can see in the photo. the cap and hole jewel are removed...





While I expected a friction fitted hole jewel, I was surprised by this little baby. Looks to be a replacement hole jewel in a setting that was friction-fit into the balance cock...

Here's a close-up...



Examination of the balance cock itself makes me wonder if the hole hasn't been reemed out larger to accept the setting.

A Closeup... The hole is 1.9 mm in dia...




So I'm looking for suggestions. Does anybody know the proper diameter of the balance cock hole? 1.9mm seems too large for a friction fit balance hole jewel. Should I fashion another jewel in a setting and friction fit it? Oh the wonders of fixing someone elses fix

Any suggestions appreciated

Mike Miller

Mike,

I checked my Elgin MC and found that both balance jewels (upper and lower) are the same for grades 571-575. They are unset P/N 5811. Grades 542, 543 & 546 also use these jewels.

I have a grade 574 and the balance cock hole is about 140-150mm. It also has an unset jewel.

Someone has reamed the hole out on yours and tried to use something like an 0s set jewel. The pivot hole was probably too small so they tried to ream the jewel out too!

Here are typical sizes for Elgin balance jewels with settings:

12s: 2.12mm
16s: 2.41mm
18s: 2.40mm (high grade 3/4 plate)
18s: 2.88mm

Provide me with the dimensions of the jewel pictured and hole pivot size you need and I will look through my stash.

My 574 balance cock was not serialized. If yours isn't, you may want to replace it.



John D. Duvall
IHC Happy Camper 192
IHC185 Watch Repair Moderator