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  1. Richard P Dec 10, 2013

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    I'm looking for a correct specification crown for a c.1954 9ct yellow gold Omega. I had a new one fitted some time back which is too big and modern looking but was apparently the best the repairer, a vintage Omega specialist, could manage.

    Watch details are:
    - British case marked Dennison 13322 (I think, but looks like 13 6over7 22), then below that ALD 697376 (as before, looks like 697 6over7 76)
    -hallmark: Birmingham 1954-5
    -Cal: no.266

    I am not sure of the crown thread/tap number or case stem tube diameter.

    The Omega Vintage Database at omegawatches.com and ofrei.com were unable to help. Google has various images of watches like mine but the crowns seem to vary.

    Using the Cousinsuk.com search facility I came upon this page:

    https://www.cousinsuk.com/document/category/450.aspx

    and, searching against the case number 13322, the PDF 'Omega 13322 BL' seems to refer to the crown fifth from bottom on the following page:

    https://www.cousinsuk.com/catalog/watch-parts/omega-hermetic-crowns/omega-hermetic-crowns-5mm-diameter-over

    which is this:

    [​IMG]

    • Tap 12 (Ø1.20mm)
    • Crown Ø5.00mm
    • Pendant Tube Ø2.00mm
    • Crown Depth 1.80mm
    • Gold Plated
    • Omega 35002SX

    which seems to be the same as this one on ebay, that the seller says is suitable for a Cal 266:


    http://www.ebay.co.uk/itm/1x-Omega-NOS-Yellow-Gold-Crown-and-Stem-for-Cal-260-269-280-286-30T1-30T2-/121231306681?pt=UK_Jewellery_Watches_WatchAccessories_SpareParts_SM&hash=item1c39f2efb9

    All of which suggests this is the right one, but would I be better off buying a crown only or a crown and stem, and would the Cousins crown be genuine Omega new old stock?

    I assume it's not really necessary to change the stem if the stem is OK, as well as being a simpler job.

    I'd be grateful for any advice or comments.

    Thanks.
     
  2. Archer Omega Qualified Watchmaker Dec 10, 2013

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    Regarding the stem, sometimes the length of the threads in the crown will vary, so when you screw the stem into the crown it will bottom out in order to tighten it - if the threads are deeper in the crown, it may cause the stem to be too short. If the threads in the replacement crown are shallower, then you can always trim the stem. When I'm swapping a crown I always have a stem handy in case I need to cut a new one to the correct length.

    I know people who bodge these things by putting Loctite on the threads and not fully screwing the stem into the crown to make up for a short stem, but that's not proper watch work IMO. Another trick is to put something in the crown hole, like a small piece of lead, which will then get compressed and make the hole shallower - I just use a new stem - much easier.

    Cheers, Al
     
  3. hoipolloi Vintage Omega Connoisseur Dec 10, 2013

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    I won't worry too much about the crown thread and stem, the color matching is more important.
     
  4. John R Smith Dec 10, 2013

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    Al - what tool do you use to cut the stem, so as to avoid damaging the start of the thread? When I cut small bolts to length, I always thread a nut onto the bolt first, so that I can turn it back off and re-form the thread after it has been cut. But I don't suppose that trick is applicable here ;)
     
  5. Archer Omega Qualified Watchmaker Dec 10, 2013

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    I just use side cutters, and then file the end of the stem to a point with a small file. This provides a chamfer that allows you to start the threads easily. Also if you prepare the end of the stem this way, there is no need to use Loctite on the threads - the only stems I use it on are for quartz watches where the stem is so thin it will break when you try to torque it into the crown.

    If you cut as many stems as I do, you learn pretty quick how to do it fast and efficiently.

    Cheers, Al
     
    JimInOz and John R Smith like this.
  6. Richard P Dec 11, 2013

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    Thanks for your replies. Would I need just the crown and the stem or is there another piece between that is required?
     
  7. John R Smith Dec 11, 2013

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    It's just the crown, and as Al says, a spare stem would be sensible. Were you intending to do the job yourself?
     
  8. Richard P Dec 11, 2013

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    No, I'll ask someone to do it, I am an owner with no watchmaking skills. From what I gather, there's little or no advantage to getting a 'factory fitted' crown and stem combination which according to the seller can just be slotted into a cal 266 if the two correct parts can be got elsewhere, just screwed together and then slotted in. Thinking more about it, probably I should get the opinion of the man who will do the work - my reluctance so far is that it was done wrong last time by someone who maybe should have known better.
     
  9. John R Smith Dec 11, 2013

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    It would be a very good idea to involve your watchmaker at an early stage.
     
  10. Richard P Dec 12, 2013

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    I am sure you are right, thanks again.