Odd Size Jewel - Help?!

[mzinski]

I have a Patek caliber 28-255 (same as AP 2120 or Vacheron 1120) with a broken jewel in the combined barrel bridge (part 106). I measured the jewel before removing and the hole after removing as well as the part that sits in the jewel. 

The interior hole size needs to be 1.10. 

I measured the existing hole in the bridge at 1.74mm, which would lead me to look for a 1.75mm outside diameter jewel. Ideally, I would get a 110x175 jewel. I suppose I could look for a 110x180 and increase the hole size if required. 

The closest size I found was 110x170 center jewel. Even though I measured several times, I assumed I must have measured wrong and ordered this one. Didn't fit. 

Can anyone help me find a replacement jewel of an odd size like this? 

Worst case, I'll turn a brass bushing or buy a replacement bridge but I'd rather not. 

[clockboy]

Can you go up a size and ream out the jewel hole on the plate to fit.

 

[mikepilk]

4 hours ago, mzinski said:

I have a Patek caliber 28-255 (same as AP 2120 or Vacheron 1120) with a broken jewel in the combined barrel bridge (part 106). I measured the jewel before removing and the hole after removing as well as the part that sits in the jewel. 

The interior hole size needs to be 1.10. 

I measured the existing hole in the bridge at 1.74mm, which would lead me to look for a 1.75mm outside diameter jewel. Ideally, I would get a 110x175 jewel. I suppose I could look for a 110x180 and increase the hole size if required. 

So a jewel with a 1.10 mm hole, and 0.325 mm wall thickness !  They must be hard to make.

[nickelsilver]

It's kind of odd that they went with an exterior size that's not a full 10th of a mm, but they certainly ordered these specifically for this caliber (and it's been around quite some time) so they could spec whatever they wanted. Something to be careful of is the jewel thickness- this is an ultra thin caliber, and the original jewel is probably going to be thinner than anything available as a generic jewel. If you can make a bushing to fit a smaller jewel, and have some beryllium copper bar, I would bet that a nice bushing made from that as a replacement for the jewel will work just fine. Then you can fit it to the original hole, and nothing has been changed on the watch.

 

I'm curious where you found one 1.10/1.70- do you mind sharing the supplier?

[mzinski]

1 hour ago, nickelsilver said:

It's kind of odd that they went with an exterior size that's not a full 10th of a mm, but they certainly ordered these specifically for this caliber (and it's been around quite some time) so they could spec whatever they wanted. Something to be careful of is the jewel thickness- this is an ultra thin caliber, and the original jewel is probably going to be thinner than anything available as a generic jewel. If you can make a bushing to fit a smaller jewel, and have some beryllium copper bar, I would bet that a nice bushing made from that as a replacement for the jewel will work just fine. Then you can fit it to the original hole, and nothing has been changed on the watch.

 

I'm curious where you found one 1.10/1.70- do you mind sharing the supplier?

Ofrei had some 110x170 center jewels. 

[nickelsilver]

Ah thanks I see it now, I scrolled to the bottom of the OF page thinking they'd be sorted by hole size. I don't have anything remotely that small of outside diameter at 1.10 hole in my Seitz assortments, was wondering of there was another source.

[mzinski]

4 hours ago, nickelsilver said:

It's kind of odd that they went with an exterior size that's not a full 10th of a mm, but they certainly ordered these specifically for this caliber (and it's been around quite some time) so they could spec whatever they wanted. Something to be careful of is the jewel thickness- this is an ultra thin caliber, and the original jewel is probably going to be thinner than anything available as a generic jewel. If you can make a bushing to fit a smaller jewel, and have some beryllium copper bar, I would bet that a nice bushing made from that as a replacement for the jewel will work just fine. Then you can fit it to the original hole, and nothing has been changed on the watch.

 

I'm curious where you found one 1.10/1.70- do you mind sharing the supplier?

If you were to make the whole thing out of copper/brass/etc and forego the jewel all together, what material would you use? 

[Nucejoe]

Whats the budget for the correct jewel?  

 

   

 

[mzinski]

1 hour ago, Nucejoe said:

Whats the budget for the correct jewel?  

 

   

 

Good question. Nothing necessarily set but I would like to target $50 +/-

Why? A new (used) bridge off eBay is $250. I don't want the price of a new jewel to get too close to a full replacement cost. 

[Nucejoe]

1 hour ago, mzinski said:

Good question. Nothing necessarily set but I would like to target $50 +/-

Why? A new (used) bridge off eBay is $250. I don't want the price of a new jewel to get too close to a full replacement cost. 

This price neccesitates no covert CIA operation.  So I hush up. lol

 

[mzinski]

3 hours ago, Nucejoe said:

This price neccesitates no covert CIA operation.  So I hush up. lol

 

If you can get me the jewel - proceed with covert actions

[mzinski]

Well, in the end I’ve been unable to find a jewel of the right size so I’ve opted to replace with a brass bushing. Perfect fit and the wheel moves beautifully.