What a difference a crystal makes...

There's a dial before me...

I picked up this 166.002 Seamaster in RG plate a month or so ago. Has a nice 565 inside. The crystal was very marked and did not respond to polywatch so time for a replacement. This is how the watch looked earlier today:


As an amateur, crystal fitting can be a bit tricky as there seems to be a lot of force involved in pressing it in. Anyway, have not had any disasters yet. So, remove the movement and push the old crystal out, then clean the groove where it sits. This is some of the dirt that came out of the groove. Essential to have that clean before trying to insert the new:


I was unable to get a crystal with an RG tension ring so am forced to reuse the old one on the left below. I wouldn't recommend this as a new one requires far more force to insert so is clearly clamping better to the case but, this will work and am not using it for diving. Obviously, gave the whole case a clean as well.

Out of interest, the Z in the part number is a steel tension ring and I think they go like this: W is black; X is yellow; Y is pink; Z is stainless. Thanks to @Archer for that info.

Crystal pressed in and now the dial looks far more impressive. Really do need to clean the hands but will do that when I service it. I even put the Omega symbol in the correct orientation unlike the old one as it annoys me when they're out of alignment...



Cheers, Chris

I know what you mean Alpha. To be honest, you don't notice it on the wrist but once you know it's not aligned... Stunning De Ville you're wearing!

looks Good... Great work!

I have a screw down case press and the crystal tends to spin as you tighten it, so it's a PITA to get the logo straight and I usually settle for "good enough."

I dig it. Definitely an improvement.

Very nice dial and case.

I noticed that also genuine vs non genuine crystal, even in perfect condition, looks much better. I don't know if it's the different curvature or a different material but the genuine crystals really make the dial pop.

Nice job, those are really lovely watches and with the black dials I think outstanding values today.

I found a few watches with the generic and two with original Omega. The crystals are the same height, but the generic has a longer vertical surface and a rather sharp curve. The Omega crystals have a more gradual curve and a shorter vertical surface coming from the bezel. From above this you can't see this edge, but the sharp curve on the generic makes the very outside of the dial less visible. And if you are looking at the dial from a low angle the sharper curve distorts what you can see.

Okay yeah I can see the difference, but to me I'm not sure if I would choose the more expensive one. For $10 dollars vs $45 I would probably choose the generic. A*F Swiss makes a crystal I am happy with. If I could source these for more like $25 dollars I may choose the better crystal though.

Actually, it's possible that the original is a better fit. I had one heck of a time installing the generic crystals in Omega cases, and I have heard people say that they could only fit the original Omega crystal.

I think the original crystals are just better made – that might not explain the huge price difference but some of the cheaper crystals distort the dials and are not completely transparent. I believe the big supplier for plastic (or hesalite) non OEM crystals is Sternkreuz. I can’t believe that their crystals are that badly made so, for the next one I do, I will buy one of theirs, an AF and an Omega to see if I can make a meaningful comparison of transparency and water resistance.

At the end of this year, the Omega ones will not be available to tinkerers so might be an idea to find an alternative now. Shame really as I like to use original parts. I know the crystals are expensive but I'm not that hard on them. Still on the original crystal of my late 90s Speedmaster.

I really like the 166.002 as well. It’s virtually all dial so looks like a larger watch on the wrist in comparison to other similar sized watches of this era.

Maybe I will invest in a few crystals of the most common size.