Tudor Caliber T601

The Tudor caliber T601 is a Swiss made automatic movement with 25 or 26 jewels.

Tudor T600 VS T601:

There is a similar Tudor caliber T600. There are watch articles online stating that the difference between the caliber numbers T600 and T601 is that one is based on the ETA 2824-2 and the other is a Sellita SW200-1. This appears to be incorrect. In the current (2021) Tudor catalog, all of the T600 watches are no-date models, whereas the T601 watches have a date.

• T600 – No date
• T601 – Date at 3:00

Nowhere in Tudor’s marketing information do they assert that the distinction between these calibers is the base movement used. We’re not sure where big watch media is getting their information.

We have an email out to Tudor for confirmation and will update this post if any clarity is provided.

Tudor T600 AKA 2824-2 / SW200-1:

The T600 is said to be based on either an ETA 2824-2 or a Sellita SW200-1. You may see other sites incorrectly list the T601 as being based on a Sellita 2834 or ETA 2429. There is no such thing as a Sellita 2834 or ETA 2429. There is an ETA 2824-2 which the Sellita SW200-1 is a clone of. Therefore, if you get a T601 based on a Sellita SW200-1, then perhaps it can be called a clone of a clone.

Tudor used to refer to their ETA 2824-2 based movements as Tudor 2824. In 2020 the name changed to T601. Perhaps this was a way for them to deal with the fact they were starting to use Sellitas. If this is the reason behind the new naming convention, it would have been nice for Tudor to disclose the use of Sellita movements since many collectors expect their non-in-house movement Tudors to have an ETA inside.

So which one is it… ETA or Sellita?

Which one you get may be completely random. If true, this wouldn’t be the first time we’ve seen watch brands slap their own caliber number over a 2824-2 or clone and consider them one in the same (pro-info: they are not exactly one in the same as not all parts are completely interchangeable, but close enough). Why do brands pull this? Because it depends on the supply they are able to get their hands on, especially since ETA movements became unavailable in early 2020. If your T601 powered watch was manufactured before mid-2020, it likely has the ETA.

Editor’s Observations: One of the brands we’ve seen doing the rebranding of ETA or Sellita, luck-of-the-draw, box of chocolates movement games is Norqain. Tudor also happens to make Norqain’s “manufacture” movements. The apples don’t fall far from the tree!

What modifications made by Tudor?

The most obvious modification is the rotor, changed from stock to include Tudor branding. In the past, Tudor modified ETA movements with KIF anti-shock protection, which have been used by Rolex for years. Another modification Tudor has been known to make to the ETAs is changing the ETACHRON regulating device to a Triovis precision regulator.

As for the Sellita versions of the T601, it is unconfirmed whether the same modifications are made. If you have a genuine Tudor powered by a Sellita based T601 and have access to opening it up, please post a picture in the comments.

With either base movement, Tudor adjusts them to 5 positions.

Is it an officially certified chronometer?

Although Tudor does not write “Chronometer” across the dials of T601 powered watches, the Tudor marketing department describes the T601 as having “chronometer performance“.

So does “chronometer performance” means is it an officially certified chronometer or not? This sounds like they are claiming a chronometer-like timekeeping experience, without an actual chronometer certification to go along with it. If this is the case, it could be that they are using a Premium grade Sellita (or Top grade if it’s an ETA) which runs close to COSC spec but without the official certification.

For example, Sellita’s Premium grade is tested in 5 positions and tests out at an average of +/- 4 seconds per day with a maximum divergence of 15 seconds/day. For COSC, the movement must keep time within an average rate of -4/+6 seconds per day over the span of testing (at least 15 days).

T601 Hush Hush:

Tudor themselves seem to be not so impressed by the T601. Case in point:

In 2021, Tudor announced the 1926 in four sizes (28mm, 36mm, 39mm, 41mm). All sizes, except for the 28mm, are powered by the T601. In the official 8 page marketing pdf (source), Tudor describes the T601 like this:

“Swiss self-winding mechanical Calibre T601 … with chronometer performance“

Interestingly, T601 is only mentioned twice in the entire marketing material – once for the quote above and once in the specs list. In contrast, the Black Bay Ceramic was released at the same time but mentions its so-called “Manufacture” caliber MT5602-1U a total of 6 times in 8 pages. One entire page is dedicated to the MT5602-1U with a picture of the movement. At the same time, not one single image of the T601 is to be found on the Tudor site (if you locate one, please share in the comments below).

Caliber T601 Warranty:

Watches powered by the Tudor caliber T601 movement are covered by a 5 year manufacturer’s warranty. Actually, Tudor calls it a “guarantee” rather than a warranty. Tudor clearly states that this guarantee is transferable, so when you purchase a pre-owned watch or sell your watch, it will still be covered within five years from the original date of purchase. Tudor also states that no registration is necessary for coverage, nor are periodic maintenance checks.

Recommended Service Intervals:

Tudor recommends that its watches be serviced approximately every 10 years depending on the model and real-life usage.

List of Tudor watches with caliber T601:

As of this post, the Tudor official site shows 278 model configurations with the T601 movement.

Retail prices range from $2,375 to $6,825 USD depending on configuration.

Pros and Cons:

Pros:

• You don’t have to send it to the Rolex/Tudor Service Center aka you don’t have to pay RSC/TSC prices if you don’t want to.
• Parts are readily available for the base movement and it’s easy to find someone to work on a 2824-2 base or clone.

Cons:

• Too much smoke and mirrors and too many inconsistencies. A watch consumer should not have to do so much digging and research to figure out what powers their new luxury watch.

Additional Resources:

• Tudor caliber T600
• More Tudor calibers here

As you can probably sense from the inconsistencies revealed above, this caliber listing is in desperate need of some actual images of the T601 – ETA and Sellita based versions. If you have access to the inside of your watch or if you are a watchmaker with one on your bench, please submit images here.