I'm sure this has been asked and answered before, but having a hard time finding it.
Could someone help me clarify the difference between Swiss Made, T Swiss Made T, and Swiss Made T on the dials?

Thanks.

 

"T" is the difference.

Happy to help.

 

Which T though? There's 3.

 

Can’t forget about the Swiss-T<25 dial

But alas, I see this thread is in the Omega section…

 

just for clarity ( or is that just to add to the confusion) there are many 60s Constellations with SWISS MADE T that have tritium lume on both the dial and hands.
It had been suggested that the quantity of lume on the hands/dial was reflected by the single T but the visible evidence doesn’t support this, so it is likely to be a dial manufacturer thing.

 

Similar for the ref 166.002. Plenty of examples with Swiss Made T but lume on hands and dials.

 

It was not specified in the ISO 3157 norm so i think it is just done for esthetic reasons. From FHH site ;

SWISS T 25 (T SWISS MADE)
Swiss T 25 (T Swiss made) | Swiss T 25 (T Swiss made T) | Swiss T 25 (T Swiss made)
So that watches (and timekeeping devices in general) can be read in the dark, the numerals, hour markers and hands must be coated with a luminescent substance. As a general rule, the light emitted is either photoluminescent (using energy absorbed from a light source) or radioluminescent (using the radioactive property of the coating substance).

Radioluminescence is generally reserved for watches intended for professional use, such as military watches or diving watches, and is strictly regulated by ISO 3157 which allows only two types of radionuclides: tritium (3H) and promethium (147 Pm). Both these radionuclides emit very low-energy radiation.

ISO 3157 provides for optional marking of timekeeping devices that emit less than a certain value. This marking can be shown on the dial as follows:

• tritium-activated deposits: T
• promethium-activated deposits: Pm

In contrast, devices that emit above this value must be marked as follows:

• tritium-activated deposits: T 25
• promethium-activated deposits: Pm 0.5

"T Swiss made T" means that the watch is Swiss and contains a certain quantity of tritium that emits less than 227 MBq (7.5 mCi). "Swiss T<25" means that the watch is Swiss and contains a certain quantity of tritium that emits less than 925 MBq (25 mCi). Most Swiss watches use photoluminescent light emission, sometimes indicated by the optional marking, "L Swiss Made L".

 

The 1991 norm is long withdrawn but here is a link to pdf file :

https://cdn.standards.iteh.ai/samples/8330/b6c9072311874d95b22af387b827ce4c/ISO-3157-1991.pdf

And to FHH site ;

https://www.hautehorlogerie.org/en/...:text="T Swiss made T" means,925 MBq (25 mCi).

 

I found a T Swiss Made T Seamaster 600 from 1966. The dial is lumed but the hands aren't (they're black).
Would this mean this is probably not the correct hands? Or does tritium ever turn black after it ages?

 

Tritium can turn black but the hands could well have been replaced. Got a pic?

 

Would you give an example?

 

This thread is like being back in my first year law school classroom. No sleep for me tonight.

 

Thanks for this post -- informative.

 

What exactly is it you think you have spotted there? This is a forum about omega watches and that is not. What did I miss?

It’s not great that this thread was bumped as some of the first posts aren’t exactly correct!

 

Agree. It should be pointed out that ‘Swiss Made T’ does not mean non lumed dial but lumed hands. It means lume on both the dial and hands, just like ‘T Swiss Made T’.