IWC Cal 853 Broken Jewel

Hi all

I recently purchased this IWC Cal 853 and went on to service it , at disassembly when I removed the oscillating weight one of the jewels broke (maybe it was broken before idk)

I don’t have the knowledge or tools to find and install a new jewel , so I went to my local watchmaker , he didn’t have a correct jewel and he can’t measure the jewel size .

The watch is currently at my watchmaker so i couldn’t take a picture of the broken jewel but i added a photo from a Cal 854 which I’m working on .
The broken jewel is the one on the underside of the oscillating weight , the one that sits on the little plate connected to the weight .

If anyone here knows the jewel size , or have any idea how this could be fixed , would help me a lot .

The part you need is number 12.010.10 "heart piece with jewel for automatic"

See here: https://watchguy.co.uk/tmp/IWC 851,2,8521,3.pdf

Thank you !! , was able to find one for sale 😁
BTW , The part I purchased is an original IWC part sealed in its original packaging , the part number on the package is Cal.854 , 1152 .

The watch mentioned .

Excellent, I'm happy for you.

What a beautiful watch!!

Hi,
Wanted to update you on the part, so I purchased part no 854 , 1152.
Unfortunately it did not fit. it is not the same as the part for the 853.
my watchmaker was able to modify the part so it will fit, so good result in the end, but for future reference now i can tell this is a wrong part.
I’m adding a couple pictures from an old IWC catalog i have, it does not feature the 853, but it does feature the 852. maybe this is the correct part for the 853 as well ? 85 20 14.