Earliest serial number for caliber 321

fascinating thread...I got lost somewhere on the first post but kept going through with no little amount of admiration.

It is... An 18ct gold chronograph with large 'fancy' lugs:

Patek cronographs do not occur very often on the workbench, but the very few I have dealt with worked flawlessy. Please remember that, even if the base caliber might be considered the same, these watches are, obviously, in a totally different class from Omegas. As such, components and materials are very, very different and this is the case also for the minute jumper spring, which cannot be compared to the original.

Of course they kept it that way - no wire springs are allowed in a Geneva seal (or now Patek seal) watch...

Cheers, Al

The following are the requirements for obtaining the Geneva Seal Hallmark:

GENEVA SEAL CRITERION NUMBER ONE (A)
The workmanship of all the caliber's components, including those of additional mechanisms, must meet the requirements of the office for optional inspection of Geneva watches.

GENEVA SEAL CRITERION NUMBER ONE (B)
Steel parts must have polished angles and their visible surfaces smoothed down. Screw heads have to be polished, with their slots and rims chamfered.

GENEVA SEAL CRITERION NUMBER TWO
All movements must be provided on the train and escapement with ruby jewels having polished holes. On the bridge side, the jewels must be half frosted with polished sinks. The endstone for the center wheel on the baseplate is not required.

GENEVA SEAL CRITERION NUMBER THREE
The balance spring should be pinned up in a grooved plate with a stud having a rounded collar and cap. Mobile studs are allowed.

GENEVA SEAL CRITERION NUMBER FOUR
Split or fitted indexes are allowed with a holding system except in extra-thin calibers where the holding system is not required.

GENEVA SEAL CRITERION NUMBER FIVE
Regulating systems (balances) with variable radius of gyration are allowed provided they comply with criteria ONE (A) and ONE (B).

GENEVA SEAL CRITERION NUMBER SIX
The wheels of the going train have to be chamfered above an below and have a polished sink. In wheels 0.15mm thick or less, a single chamfer is allowed on the bridge side.

GENEVA SEAL CRITERION NUMBER SEVEN
In wheel assemblies, the pivot shanks and the faces of the pinion leaves have to be polished.

GENEVA SEAL CRITERION NUMBER EIGHT
The escape wheel has to be light, not more than 0.16mm thick in large calibers and 0.13mm in calibers under 18mm, and its locking-faces have to be polished.

GENEVA SEAL CRITERION NUMBER NINE
The angle traversed by the lever is to be limited by fixed banking walls to the exclusion of pins or studs.

GENEVA SEAL CRITERIA NUMBER TEN
Movements fitted with shock proofing are accepted.

GENEVA SEAL CRITERION NUMBER ELEVEN
The rachet wheel and the crown wheel should be finished according to registered patterns.

GENEVA SEAL CRITERION NUMBER TWELVE
Wire springs are not accepted.

However, please do not forget the main objective of this discussion: thanks to the received contributions we ascertained tha the earliest copper colored 321 should fall in the serial range 12,490,122 - 12,490,252 but it still remains to find a picture of it! 😀

GIYF!

Of course! All our knowledge would not be the same without the Internet!
Al, as I understand you are younger than me and I do not think that you have ever experienced looking for spares by regular mail. An exciting experience, though! 😎

No I have not, but I do have a lot of old parts envelopes where the watchmaker wrote "Please supply 3 parts per sample" on the envelope, and sent it off to the local material supplier by snail mail. Some days I think that would be much easier than looking up parts for hours on the internet...just mail off the old part and wait for someone else to do the searching!

Oh, and I learned most of what I know about the Geneva seal requirements while touring the Vacheron Constaintin production facility in the Plan-les-Ouates area. They made quite a lot of being a maker that met those requirements. When I went through the Patek factory, they didn't emphasize it as much, but that was not far away from the launch of their own certification, so that may explain why they didn't say much about it. Also, some makers who use the Geneva seal get away with murder, so the value of the seal has been diminished for sure, at least in my view...

I have been several times at Patek factory in the Eigthties, but I have never toured Vacheron Constantin. Even at that time folks at Patek did not insist much on the Geneva seal but my impression has always been that they consider themselves in a league of their own.
However, I must admit that most of my knowledge about isochronism comes from them.

Gentlemen, I understand that we have gone as far as the knowledge of this forum may allow.

We ascertained tha the earliest copper colored 321 should fall in the serial range 12,490,122 - 12,490,252 and, even if no one has been able to provide a picture of one of these movements, I would like to express my gratitude to all the contributors to this topic.

Cheers,

Maurice

Just as Nobel Prize wrote earlier, a fascinating thread.

Please could you specialists have a look at the thread that I have just started about earlier Omega chronographs, leading up to the 27/321?

Tom

One of the short-lived white 27 CHRO 321 engraved.

I know the thread is old. I recently bought a 27 CHRO C12 with the movement number 93906XX:
https://omegaforums.net/threads/omega-2279-27-chro-c12-multiscale-1942.155545/

Are there any new additional information available in the meantime? Would be very interesting.

These early calibers may present sensible variations: a picture is necessary in order to post any comment.

Here is a picture of the movement. Hope it is good enough

Another one, that is not so much overexposed, thanks

That steel/steel colour early 321 is truly a stunner. I am at a loss for words. At the risk of sounding painfully ineloquent. What a pretty movement! WOW!