Jump to content

Jewel measurement and ordering sanity check

mbwatch
 Share

Recommended Posts

mbwatch WRT Addict

mbwatch

Posted
Posted

Hi all - I am working on a Langendorf pocket watch movement which needed the lower balance hole jewel replaced. This is my first time reaming, measuring, ordering a new jewel and I need to check with you experts if I made a mistake in ordering or if ofrei made an error in selecting the jewel they sent me. I did a load of research to prepare for this repair.

I reamed the hole up to a reamer measuring 1.19mm and my pivot measures 0.11mm. I ordered a convex olive hole balance jewel 12/120. I received the jewel in an envelope hand written 12/120.

When I went to press in my jewel, it fell straight through the hole with ease. I measured it with the most accurate equipment I have and I am getting 1.00mm.

So my novice question for you today is did I misunderstand the measurement and ordering or did the vendor send me the wrong diameter jewel at 100 instead of 120? Another way to ask this stupid question is should a 120 jewel order measure 120 or did I miss a detail?

PXL_20240604_014103167.thumb.jpg.6e18582547feb178bacabfa77b8c7e17.jpg

Link to comment
Share on other sites
nevenbekriev Super WRT Addict

nevenbekriev

Posted
Posted

No need to doubt, You have received the wrong stone. 120 is 120 and will allways measure 120 as out diameter.

What You did wrong is that You reamed the hole to 119, believing that this is the right way to fit new jewel there. Actually, the original jewel was rolled there and the hole and surrounding place has dedicated shape, and there often is no enough 'meat' to ream the hole and have normal walls as result, that will hold the pressed new type of stone right.  Often the decision is to ream enough so the surrounding of the hole is gone and make a bush that fits in this new hole, and the bush internal hole will take the stone. So now You can do just the same - ream more, fit bush in place and fit the stone in the bush.

Link to comment
Share on other sites
mbwatch WRT Addict

mbwatch

Posted
  • Author
Posted
3 hours ago, nevenbekriev said:

What You did wrong is that You reamed the hole to 119, believing that this is the right way to fit new jewel there.

Thank you for your confirmation! I am aware the original jewel was burnished in place and that those jewels are almost impossible to source today so I thought I would try pressing one in. The original hole was smaller than 120 (probably 100), and I have reamed out all of the original bush to fit the 120 jewel. Since this watch is for my own collection and not valuable I will attempt to press in a 120 jewel directly and if it cannot hold I'll eventually need to produce a new bush for it.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
 Share
Go to topic listing


  • Recently Browsing

    • No registered users viewing this page.

  • Topics

  • Posts

    • Terrinecold
      Broken Omega advice

      By Terrinecold · Posted

      Of course I talk at work about my new watchmaking hobby. So my manager told me that his son has a watch from his grandfather (the son not the manager) which has great sentimental value but is not working anymore.  A vintage omega. He told me they hear something rattling when they shake it (not a good sign I would say). I told him I didn’t feel confident enough to even open it and look at the interior. Let alone try to repair it.  But I could post here for advices.    from the pictures is there a chance to identify the movement and to know if parts would be available.    Also does someone know a reputable watchmaker around Boston who could take a look and how much a diagnostic could cost (of course I assume repair price would depend on what is wrong).   
    • Nucejoe
      Omega cal 1012 not holding power

      By Nucejoe · Posted

      @AndyGSi   winds with back removed on Bergeon winder ,  because he wears it for 2 days ,  but stops after 2 days on wrist, so its not winding with case back installed. Unless he wears with case back removed.        OP has done the tests, just not clear .      
    • ManSkirtBrew
      Repairing stem threads

      By ManSkirtBrew · Posted

      I finally have a replacement crown for the Longines I'm working on and I can't get the stem to thread cleanly into the crown. It goes in a fraction of a turn and stops. Not about to force it, I tried a different stem and it threads into the new crown just fine. The first thread looks a little smushed to me, but it could also be an optical illusion from having been filed at a weird angle. I obviously can't shorten it to get to fresh threads, so what would you do here?  
    • rehajm
      Vintage vulcain cricket service uk

      By rehajm · Posted

      …a fine choice and the first I purchased to rescue. Keeping it forever… The Vulcain 120 is unique with the alarm complication but isn’t an overly complex movement to service. Any professional experienced in servicing vintage watches should be up to the task…
    • Neverenoughwatches
      Broken barrel arbor.

      By Neverenoughwatches · Posted

      Thanks John, i will definitely look into those for future turning . As a temporary measure to keep me going today i reshaped and sharpened a carbide drill used on  porcelain tiles. It cuts the blued steel perfectly.  As always appreciate the information John. 
×
×
  • Create New...