Bezel and Crystal - General consensus regards to size tolerances

[mongobongo]

Hi!

Since looking into refurbishing my grandfathers watch that was passed on to me I would like to ask the following.

Is there a general consensus as what are the tolerances when we match a bezel with a crystal ?

I will use my current predicament as an example.

After finally figuring out what the correct crystal is for my watch (25-123), the external diameter of this crystal is 294 mm according to the documentation I have found on the Internet (will link this below, is there not a resource here at the forums that this information can go into ??)

Esslinger rolex-chart-case-number-and-crystal-number (used this document to find out the correct crystal for my 9061/0)
Ofrei page419 Generic Crystals to Fit Rolex® (used this document to get the dimensions, "cyclope 123")

Now to the bezel,

I have found the following bezels whose dimensions have been recorded.

These bezels are for a 25-117 crystal that has an external diameter of 295 mm, that is 0.1 mm bigger external diameter than the 294 mm of the 25-123

The following bezels for the Rolex 1501 are available at chrono-shop net
293.5 mm
293.2 mm
293.0 mm
292.4 mm
292.4 mm
291.8 mm
290.4 mm
282.0 mm

Such a variation in measured diameters and all these bezels internal diameters are smaller than the crystals exterior diameter.

i.e. best case scenario,

crystal external diameter: 295 mm (or 294 mm in my case)
bezel internal diameter: 293.5 mm

So the question is as follows, are the bezels meant to be slightly smaller, in so that there is a degree of "stretch" that will take place when the bezel is placed over the crystal to form an air tight seal ??

I need to also buy a bezel and as my bezel has a split on one side and the measurement ive taken cant be used to choose the 'correct' sized bezel.

Thanks

[linesiders]

I would get the bezel first and then crystal.

First recommendation. Get the bezel first. Is the bezel an Engine Tuned or smooth? Get an original Rolex one on Ebay; NOS (preferred) or used, not aftermarket. Once with bezel search for a correct Rolex service crystal. This will cost a little more than Ofrei, but with some good hunting, not too much more. The reason crystals sometimes have different measurements is that this is friction and compression to make this hold together.

Sometimes you see used bezels on the market because they have loosened over time, you may purchase one that is looser than you would like with obvious ramifications.

[mongobongo]

Originally Posted by linesiders

I would get the bezel first and then crystal.

First recommendation. Get the bezel first. Is the bezel an Engine Tuned or smooth? Get an original Rolex one on Ebay; NOS (preferred) or used, not aftermarket. Once with bezel search for a correct Rolex service crystal. This will cost a little more than Ofrei, but with some good hunting, not too much more. The reason crystals sometimes have different measurements is that this is friction and compression to make this hold together.

Sometimes you see used bezels on the market because they have loosened over time, you may purchase one that is looser than you would like with obvious ramifications.

Hi,

thanks for your reply.

I already purchased the crystal as I found it at a very good price, it was sold to me as OEM (Rolex/Tudor) and looking at the pictures it has all the characteristics of the original crystal which was damaged by heat, where as the after market versions dont have one very distinguishable characteristic.

That is, the OEM version also had a 'lip' on the bottom of the crystal.

The crystal wont arrive for a while as there is no shopping from France to Cyprus at this moment in time.

Yes the bezel is an "engine tuned" version, I had some pics I wanted to post but that is not possible at the moment (newb to the forums ....).

Your advice is sound, but as finding an OEM 25-123 at such a good price (around 20-30% less than other sellers) I had to snatch it up.

Nevertheless,

from the numerous rolex 1501 bezels at chrono shop, they are ALL smaller than the diameter of the 25-117 crystal, so there must be some sought of tolerance guideline, hence the reason for my question.

[Kingface66]

Originally Posted by mongobongo

The following bezels for the Rolex 1501 are available at chrono-shop net
293.5 mm
293.2 mm
293.0 mm
292.4 mm
292.4 mm
291.8 mm
290.4 mm
282.0 mm

You’ve got the decimal point in the wrong place. It should be 29.35, 29.32, etc.

Also, bezels can be manipulated, and even tightened. I realize it’s a different model, but I brought a 1680 to the RSC in NY last year and they managed to tighten a very loose bezel. There’s a Rolex-made tool that the technician used and was able to ever so slightly decrease the diameter (it turns out the seller mixed up two Subs and I was given the wrong bezel and insert...a fact I leaned AFTER the RSC visit!).

[RyanPrasad]

At one point I had my 1601 serviced at what used to be the RSC in San Francisco, they replaced the crystal. It had a flutted WG bezel and about 18months later I woke up one day and the bezel had a crack in it that broke fully through, it was a hairline and you could barely see it but you could pull the bezel right off. I louped it to make sure that it wasn't that I had dropped it and you could see there was no ding or impact marks so it was clearly a pressure snap. I took it to a different RSC (Sydney) and after a good amount of back and forth the agreed that it was a pressure crack and that the crystal was most likely a micro-MM Off and that is what caused it.

Point being that the 0.01-0.02mm difference in diameter might not seem like an issue but some of these parts are so specific that problems end up occurring down the line even if they seem OK at first.

[linesiders]

Originally Posted by Kingface66

You’ve got the decimal point in the wrong place. It should be 29.35, 29.32, etc.

Also, bezels can be manipulated, and even tightened. I realize it’s a different model, but I brought a 1680 to the RSC in NY last year and they managed to tighten a very loose bezel. There’s a Rolex-made tool that the technician used and was able to ever so slightly decrease the diameter (it turns out the seller mixed up two Subs and I was given the wrong bezel and insert...a fact I leaned AFTER the RSC visit!).

Rolex 1006 tool $6,000-10,000 if you can find one ; )

[Kingface66]

Originally Posted by linesiders

Rolex 1006 tool $6,000-10,000 if you can find one ; )

Ouch! But, I certainly wasn’t suggesting the OP buy one, just that it’s a thing.

...a thing that I have NO clue how it works! I begged the RSC technician to let me come back and watch the process, but he just smiled and politely explained that “that is not done here.”

[mongobongo]

Originally Posted by Kingface66

You’ve got the decimal point in the wrong place. It should be 29.35, 29.32, etc.

Also, bezels can be manipulated, and even tightened. I realize it’s a different model, but I brought a 1680 to the RSC in NY last year and they managed to tighten a very loose bezel. There’s a Rolex-made tool that the technician used and was able to ever so slightly decrease the diameter (it turns out the seller mixed up two Subs and I was given the wrong bezel and insert...a fact I leaned AFTER the RSC visit!).

Thanks for pointing that out, unfortunately I cant edit that post. Some size watch

That tool must be quite a thing!

Just thinking about the mechanics involved with that is pretty cool, to be able to compress such a small metalic structure while keeping its shape and form intact!

Originally Posted by RyanPrasad

At one point I had my 1601 serviced at what used to be the RSC in San Francisco, they replaced the crystal. It had a flutted WG bezel and about 18months later I woke up one day and the bezel had a crack in it that broke fully through, it was a hairline and you could barely see it but you could pull the bezel right off. I louped it to make sure that it wasn't that I had dropped it and you could see there was no ding or impact marks so it was clearly a pressure snap. I took it to a different RSC (Sydney) and after a good amount of back and forth the agreed that it was a pressure crack and that the crystal was most likely a micro-MM Off and that is what caused it.

Point being that the 0.01-0.02mm difference in diameter might not seem like an issue but some of these parts are so specific that problems end up occurring down the line even if they seem OK at first.

Great story, thanks for sharing your experience.

So there must be a value for the tolerance, ideally i need to find the interior diameter of a new "engine tuned" bezel for a 1501 and seeing we know the exterior diameter of an OEM 25-117 crystal the difference between the two would give me a rough idea of what the tolerance is.

Originally Posted by linesiders

Rolex 1006 tool $6,000-10,000 if you can find one ; )

There is one on ebay right now, asking price $7,900.00

Originally Posted by Kingface66

Ouch! But, I certainly wasn’t suggesting the OP buy one, just that it’s a thing.

...a thing that I have NO clue how it works! I begged the RSC technician to let me come back and watch the process, but he just smiled and politely explained that “that is not done here.”

Sorry for the slow replies, a moderator has to publish my posts and with the different time zones we are in I cant get back to your replies quickly enough .....

Oh and and i am using the 1501 as my "base" as I cannot find an "engine tuned" bezel for my watch. Just noticed I have not said what my watch is, its a Tudor Oysterdate Prince 9060/1 from 1978 and has an "engine tuned" bezel.

And from what I have researched, Tudor Rolex's from this period of time shared similar parts as their Rolex cousins and seeing that the 1501 come with "engine tuned" bezel ive made the assumption that these bezels are going to be the best bet for me to find a replacement from the grey market.

This is the main reason why I need to find out the tolerance so I know which bezel to buy...