Rolex T SWISS T and Swiss-T <25 – What Does it mean?
There are many small details on Rolex watches that you may not even pay a second thought to at first glance. Rolex is a company that is all about evolution, not revolution. As such, the company consistently improves and refines its products, making small tweaks of visual details, materials used, and technical improvements. All of this is to improve their durability, reliability, and overall performance.
But if you have looked at a Rolex watch and found the text ”T SWISS T” or ”Swiss-T <25”, or perhaps ”Swiss”, printed at the bottom of the dial at 6 o’clock, what does it mean?
The fact is that the different Swiss printings on the Rolex dials actually indicate something, and are not just there for decoration.
Rolex T Swiss T and other Swiss made dial printings
Rolex has used a number of different Swiss made printings on its dials over the years. And the printing actually relates to the luminous material used for the indices and hands.
In its early days, Rolex used radium paint for the luminosity of its watches. These early Rolex watches have ”SWISS” printed at the bottom of the dial at 6 o’clock. The catch is that Rolex would also later come to use the same printing again (more on that later). Radium, as you know is extremely radioactive and due to health concerns, and the introduction of new luminous materials over time, Rolex eventually replaced the radium paint
Swiss-T <25, T SWISS T, T Swiss Made T
Rolex replaced the radium with tritium, and the above markings were used on the radium watches to indicate such. The benefit of tritium is that it is not dangerously radioactive. It does, however, have a half-life of 12 years, which means that over the years, it will lose its glow.
Rolex used tritium up until the 1990s when it replaced it with yet another material. Rolex changed to luminova around 1999. Rolex used lumina for a relatively short period of time, and this can be seen with the watches that have ”Swiss” printed on the dial. These watches are referred to by collectors as ”Swiss only”, as they only feature the Swiss text.
Later on, Rolex changed to Superluminova, and now, Rolex has ”Swiss made” on all of its watches. However, in recent years, Rolex has started printing the logo coronet between Swiss and Made, to indicate that the watch has a second-generation movement.
So what do all of these dial prints mean?
“T Swiss made T”
This printing indicates that the watch uses tritium (T=tritium) and tells us that the tritium emits less than 227 MBq (7.5 mCi). This printing also indicates that the indices are made in gold.
“Swiss T<25”
This printing means that the watch emits less than 925 MBq (25 mCi) of radioactive radiation.
Some watches don’t have any lume but still have these markings. I have an 18k Oyster Perpetual (circa 1960’s) with no luminescence on the dial or hands but still has T Swiss T on the dial.
Hi,
Yes, that is correct.
There are several dials that have these markings but no lume. If you think about it, it’s quite strange seeing that the markings are actually meant to denote the use of tritium. The logical thing would be that these dials have a different printing, but for some reason, they don’t.
Kind regards,
Millenary Watches
Well, considering these dials are mass produced — from brass disc to final finish — it is more likely they’re all just pre-printed and used across the entire Rolex catalogue.
I was under the impression that t Swiss t dials were only used on diamond dials , gem hour markers etc and if it said t Swiss made t it would have gold hour marker indices
Hi,
Not quite. The production during this period isn’t as clear-cut, but there certainly are watches with gold markers that have “T Swiss T”, although it is more common with “T Swiss made T”.
Kind regards,
Millenary Watches
Dear Millenary W.,
my Date Just 36 Gold/Steel White Bezel is from 1984-ish and has
«T SWISS T» but also has The Rolex Coronet below the roman number XII «on top»
I love roman numbers but have never seen the Rolex Coronet placed as here… Coments?
Hi,
It’s difficult to know exactly without having seen photos however, virtually all Rolex watches have the Rolex coronet placed at 12 o’clock so it sounds like it is just the way it is supposed to be.
Kind regards,
Millenary Watches
I found an old watch in a drawer cleaning out a relatives home. I’m assuming it’s not real, the bezel has a 60 instead of the normal triangle. Am I right in assuming this isn’t legit?
Hi,
It depends on the model so it’s impossible to say without further details. There are several models that have numbers on the bezels rather than a triangle, for example, the Explorer II.
If you are unsure about the authenticity of the timepiece, we advise you to take it to a professional watchmaker for assessment.
Kind regards,
Millenary Watches