...because I'm looking for an old part number. Here's the thing. I'm really into the 1970s Seamaster chrono's - and more specifically the 176.007. For this reason, I'm tagging @Andy K (our resident caliber 1040 expert) and also @Archer (because he basically knows everything). Hope that's OK For a while now, I've been obsessively trying to 'de-service' one that I sent to Omega years ago so I can restore it to its former glory. So far, I've managed to source the correct dial and (relatively rare syringe-type) hands. But I'm having some difficulties finding the crystal. The original crystal has a really nice cross section. Flat on on top, and with a smooth curve at the edges. It's the bottom one in the picture below. The service crystal has a more complex shape: no flat area the middle, and sloping downward towards the egde at various angles (the top image). It might seem like a minor thing (...and in the grand scheme of things, it of course is) but to me it does make a huge difference in the overall appearance of the watch. It makes me think of a chocolate pastille. It's just delicious! Now the thing is, it's really difficult to find an original crystal - NOS or otherwise - without knowing the part number. I know the part number for the various service crystals for a 176.007 (I think it's PE5220 / PH 5220 / PB5220 depending on the color of the tachy thing), but I'm kinda hoping the original crystal would have a different part number so that I can more easily find one. Now I know that Omega publishes something called the 'Dressing Components Catalogue', sometimes referred to as the Red Book of Parts. I was wondering if someone had a copy of a relatively old version (maybe form the 70s or early 80s) and if so, if they could do me a favour and look up the part number for the crystal. Or, if you happen to have such a crystal lying around, we could forget the whole thing
Unfortunately I do not know the part number for the domed crystal. This photocopy of the cal. 1040 technical guide from 1972 is the closest I have to the red book, but it is limited to movement parts and nothing specific to the individual case references. I'd be keen to learn as well. My 007 has the domed crystal but I'd love to replace it one day because it has a few scratches and artifacts, but I don't want the sharp-edged modern glass.
Thanks Andy! Let's hope someone has a Red Book lying around. There's a tiny little crack in my service crystal at the edge between 5 and 6 o'clock, so I'll have to replace it anyway. I'd much rather source an original crystal than spring for (...another) service one.
You could ask here if the crystal is smooth or bevelled: http://www.ebay.de/itm/Omega-Plexig...383467?hash=item1c854b37ab:g:F0kAAOSwCQZZF3Y3Purchases made through these links may earn this site a commission from the eBay Partner Network The colour of the ring does not matter, because it looks like yours is in good shape?
Thanks! I've always wondered why there are versions of the crystal with the tachy ring attached. Mine all have separate crystal and bezel. Think I could just remove the gold colored ring from this?
The rings are not fixed to the crystal. Your white ring should fit the crystal instead of the gold one. But I can not guarantee because your crystal has another shape. Maybe someone else can confirm?
By the way, if the one you pointed to on ebay is indeed the old type, then it appears it has the same part number (or at least the numbers are the same - I never saw the letters TA on the service ones).
I don't have an old red book, but maybe I can help explain a few things. The crystal part number (just the crystal) is 063PN5220 | GLASS PLEXI D36.13 H5.55. This is for the current replacement - no photos so I have no idea of the profile. The rings and crystals are separate parts and can be ought as such, but they can be bought together also. So they come in different colours, and different scales. The one shown in the eBay advert is a tachymetre scale, hence the "TA" prefix. Decimal scale would be "DE", pulseometer "PU", telemeter "TE", etc. Cheers, Al
Well, thanks to @JackDaniels83 it would appear I found the correct one! The seller sent me a number of pictures from the side, and this certainly looks like the old style to me:
Nice! One thing I'm still unclear on is whether the modern replacement has a different part number from the original. Meaning did Omega keep the part number the same and just change the shape? In other words, did your seller just look up the part number for the modern crystal and use it in the ad or did he have some original packaging with that number? I guess that begs another question, when did the design/shape change? Was it recent or has it been years/decades, etc? As you say in your original post these are minor issues in the grand scheme of things. Would be nice to know though. Either way, I'm inspired to find a replacement for mine.
You're welcome! I'm sure you were just looking for more stuff to put on your to do list That's a very good question, which I'm happy to pass on to the seller. So far, he's been a very accommodating chap.
Thanks a lot for this thread... As mine has a some scratches on the hesalite, I was about to change it.. I won't.
You don't have to change a plastic crystal because of some scratches. You can polish them in a few minutes.
On my modern service replacment 063PF5220TA tachy ring comes together.. and check picture for the chimney shape:
No, if they are as deep as in your case you have to remove the crystal, start sanding with paper No 1000 till all the scratches are gone. Then use 2000 paper till it is smooth again. Finally I'm using this: http://www.meguiars.com/en/automotive/products/g17216-ultimate-compound/ If you can not remove the crystal. Mask the case with multiple layers of strong tape and carefully start sanding. When you see that a layer of tape has gone due to the sanding, apply another layer.