lengths of Omega stem for caliber 550/552/551

[Horologist]

Whenever I had the need to replace a stem in a movement caliber 552, the genuine stems from the old silver packets fitted perfectly without any further alterations such as resizing to the case length in contrast to eta movements for example.

I replaced them in a reference 165.001,and 165.002 straight from the old stock silver foil backed Omega packets.

After recently visiting the post on
Let’s see your “jumbo” beefy lug Seamasters | Omega Forums

It has just occurred to me that the stems I have used in the above mentioned models wouldn't have been long enough to cater the jumbo 36.5mm models (such as the 55* calibers: 166.011, 165.011)?????? As I no longer have those original foil backed packets, I cannot confirm if there was a reference number for that stem of that particular length which may have been a lucky fluke that I had the right ones!!
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Unless those genuine stems came in different lengths, do the jumbo omega 55X require a stem extender to cater the oversized case???? I learn something new every day!!!! Thanks!!..

 

[kaplan]

Every stem I got was EXTRA long, maybe you somehow got a discarded stem that fit perfectly but was originally discarded because it was shortened too much?

You can also buy generic stems from Cousins UK, they are decent quality

 

[sheepdoll]

There are subtle differences in the 55x/56x/75x stems. Usually relating to the bearing tip size. I think they thickened it in some versions possibly due to wear, or thinned it to make room for the calendar or quickset. The winding clutch is pretty much the same part. The winding pinions can differ. One has to cross ref the data sheets a lot.

Most NOS stems have to be cut down to size. I still need to do that on my 351 that I found a wreak of a 2577 case for. Took forever to find the correct case clamp. Not all parts are interchangeable no matter what the sellers may think. There is also a little rusted pin what got etched out in the pickle.

I never trust the foil parts packs what can be re-closed to actually have 'new' parts in them. The paper sealed packs are probably closer to NOS yet the desiccant pad is often spent and the parts lightly rusted. So moisture must be able to get through the paper part. I suspect sellers could glue them back together.

Most watchmaking books have a chapter on making a stem. It is not that difficult just like everything else in this world, time consuming.

 

[Archer]

Horologist

Whenever I had the need to replace a stem in a movement caliber 552, the genuine stems from the old silver packets fitted perfectly without any further alterations such as resizing to the case length in contrast to eta movements for example.

You were lucky. Generally speaking, these almost always need to be cut down to size.

The stem part number is 550-1106 (full part number 72205501106) and it's 17.5 mm long.

 

[DON]

Never got a stem that didn’t need cutting. With all the cases Omega sold. It would be a nightmare to have pre cut stems

 

[Horologist]

sheepdoll

I never trust the foil parts packs what can be re-closed to actually have 'new' parts in them. The paper sealed packs are probably closer to NOS yet the desiccant pad is often spent and the parts lightly rusted.

What is most puzzling to me is that I purchased the foil packets from a supply house many years ago before the internet was so common! I thought wow! The stem was made for the movement and case without any further action or thought! I have replaced them on the Rolex Datejust (36mm case)with a carbon copy exoerience and thought the same of omega after having done the same! The only stems I had to cut are the eta and Fhf movements which is not difficult to do!

Archer

You were lucky. Generally speaking, these almost always need to be cut down to size.

The stem part number is 550-1106 (full part number 72205501106) and it's 17.5 mm long.

In my case it has been lightening that has struck twice!!! I never gave it a second thought until lurking a post on this website just recently that was totally unrelated to this topic! I then questioned if different reference numbers had different stem sizes relating from my two experiences! I bought both packets from the same supplier (6 months apart)who sold all makes and brand parts except rolex dials and cases! Both stems fitted two different omega references without cutting! Lucky, yes, but I did not learn anything from it at the time until now? !
The many wonders of leisurely browsing this forum which can be generalised to other events in life

Thanks to all of you that have responded ! Much appreciated!!

 

[Archer]

DON

Never got a stem that didn’t need cutting. With all the cases Omega sold. It would be a nightmare to have pre cut stems

They do have pre-cut stems for many watches actually...

 

[Archer]

Horologist

In my case it has been lightening that has struck twice!!! I never gave it a second thought until lurking a post on this website just recently that was totally unrelated to this topic! I then questioned if different reference numbers had different stem sizes relating from my two experiences! I bought both packets from the same supplier (6 months apart)who sold all makes and brand parts except rolex dials and cases! Both stems fitted two different omega references without cutting! Lucky, yes, but I did not learn anything from it at the time until now? !
The many wonders of leisurely browsing this forum which can be generalised to other events in life

Thanks to all of you that have responded ! Much appreciated!!

Depending on the movement, some stems come in different lengths. You specifically asked about the no stem used for no date and the early date watches (those lacking quick set), but if you look at the quick setting movements starting with the 563, they offer 2 different stem lengths as stock.

72205631106 - this one is 18 mm long

72205631125 - this one is 22.8 mm long

 

[Horologist]

Archer

. You specifically asked about the no stem used for no date

Yes, as I was still more of a novice at the time I gave as much information to the spares division as possible to avoid nasty surprises.

I vividly recall mentioning I needed it for a caliber 552 and for a particular case number. This was well before broadband internet and buying online. I also went there some months later with another Omega 552 also needing a stem as I had lost the one I took out. The salesman was himself a watchmaker that was also full of advice when I went there for any other parts. Both stems fitted perfectly in the 165.001 and 165.002 cases.

I doubt very much he would have played around resealing the packets trying to sell shortened stems. They were the only stems I had ever replaced in an Omega. I have also had the same experience replacing stems in a non date Rolex 1570 movement which has a lot of similarity to the Omega 552. I saw a common trait thinking it was all in the clever engineering and design of how everything fitted like two peas in a pod. The recent thread of the jumbo beefy lugs with 552 movements brought a de javu of what stems these models required if needed replacing, as they were 2.5mm wider in diameter than the usual 34.5mm models