Patrick’s Ponderings: How Thin Is Too Thin? Extra plate (aka Ultra Thin) Movements Explained

 By: patrick_y : February 13th, 2020-22:49

A Jaeger-LeCoultre Master Ultra Thin Jubilee in Platinum.  Photo Credit: Jaeger-LeCoultre

A lot of people ask me what kind of watch they ought to buy; apparently someone wants me to talk about watches and cares about my opinion!  I always suggest a lot of things but one of my top recommendation is to get a watch that is thin enough to fit under a shirt sleeve.  I’ve always eluded that “thin” is elegant.  Well, one of my friends ended acquiring a watch that is even thinner than the thinnest watch I owned! 

I’ve always liked thin watches.  But “thin” is an opinion, and while I can say I think most Patek Philippe 240 calibers and most Vacheron Constantin time-only pieces are quite thin timepieces, I recently thought about going “Extra-plate” (French for Ultra-thin).  Here is some of my research as I walked down my quest to acquire an Ultra-thin timepiece. 


Vacheron Constantin Extra Plate Pocket Watch.  Photo Credit: Forbes/Vacheron Constantin

Thin watches usually have thin movements; and ultra thin movement is typically defined as a movement under 2.0mm in thickness, cased up the watches are usually less than 4.9mm thick.  Piaget is an expert in this field, making the thinnest watches on record.  Thin movements are incredibly difficult to manufacture.  Here are just three examples of why they’re more difficult to manufacture than a traditional movement. 

1.     First you have the mainspring that holds all the power, as we all know these springs are flat coiled springs, but the thinner you get, the flatness becomes relatively rounder.  Say a normal spring is 2.0mm wide and 0.2mm thick; when that spring becomes 1.0mm wide and 0.2mm thick, the spring is relatively rounder.  This increases the chance for the spring to twist and coil and tangle within the mainspring housing.

2.     Secondly, and perhaps more obviously, it’s just more difficult to design a movement that is densely packed.  Furthermore, just because a movement designer can design it doesn’t mean it can actually be built.  Building an Ultra Thin movement requires a higher level of watchmaker who is more patient and more precise.  Some Ultra Thin calibers are built in a watchmaker’s Grand Complication room by the manufacture’s most elite watchmakers because they’re so difficult to manufacture. 

3.     Lastly, and this is less obvious, ultra thin movements are incredibly difficult to regulate and fine tune for accuracy.  There are fewer points of adjustment (as the design omits these adjustment points to save space) and finer tolerances.  For this reason and the reason above, Ultra Thin calibers are often built in the Grand Complication workshops of many brands due to their difficulty to manufacture.  Also, Ultra-thin movements are usually subjected to lower standards for accuracy.  Also, many Ultra-thin movements don’t have a seconds hand. 


Jaeger-LeCoultre made some thin pocket watches too.  They could fit in one's tuxedo or waistcoat without bulging out.  Photo credit: Jaeger-LeCoultre

Three Frequently Asked Questions an Ultra-Thin Buyer may have?

Why Ultra-Thin?  What’s the Point? 

Two answers; historical style and watchmaking savoir-faire.  Historically, thin watches are considered to be more elegant and more formal.  In the past, formal occasions required gentlemen not to wear watches as it was considered an insult to your host to consult the time at a dinner party.  More recently, thin watches are great for formal occasions and for individuals who want somewhat hidden timepieces.  From the artistic standpoint, a manufacture’s savoire faire and ability to produce a working, accurate, and reliable Ultra-thin movement is nothing short of remarkable.  Very few manufactures are capable to do this! 

Are There Any Real Benefits To Going Thinner?

Honestly, not really.  If you want your watch to be more difficult for others to spot, a thin watch will do that.  But do know you are wearing a timepiece that is supremely special, very difficult to manufacture, and quite rare.  At WatchProSite GTGs I see more minute repeaters than I see Ultra Thin timepieces. 


What Are the Disadvantages for Ultra Thin Watches?

There are a few; they’re more difficult and expensive to service.  They’re typically less accurate, have shorter power reserves, and are more susceptible to shocks because they have small balance wheels and are slower to recover from shocks because thee balance wheels operate at slower beats.  They usually lack a seconds hand, useful if you want to see the watch is running.  The movement is typically more fragile and delicate, extra care should be utilized when winding the mainspring. 


What Are My Favorite Models? 


Currently Produced:

Photo Credit: Vacheron Constantin

Vacheron Constantin Historiques 1955 model of watch is an incredible watch with a gold movement.  While it’s incredibly difficult to produce a movement in gold (just because F.P. Journe does this regularly doesn’t make it any less difficult), Vacheron Constantin decided to do this on an Ultra-thin caliber!  This movement is only 1.64 mm thick!  The watch follows all the proper rules for a Geneva Seal Ultra Thin movement; the movement is based on the Jaeger-LeCoultre 849 Ultra Thin caliber, but it has several modifications to adhere to Geneva Seal requirements.  This is one of the best Ultra Thin timepieces money can buy.  It may cost 50% more than a Patrimony Traditionelle (another one of my favorites), but it’s a much thinner and much more difficult watch to manufacture!  Get the Patrimony Traditionelle for daily use, and the Historique 1955 for special occasions. 

Produced in solid gold at 1.64mm, this is the thinnest movement I've ever held in my hands!  Notice the individual screwed weights on the balance wheel!  Photo credit: Vacheron Constantin


Production Stopped But Still Available:

This gorgeous dial with a beautiful sunburst and combination of printed and applied dots makes this dial look both modern and classic; minimalistic and rich.  Photo credit: Patrick_y (author).

Jaeger-LeCoultre Master Ultra Thin 38 – 849 Caliber.  The bargain that was so good that Jaeger-LeCoultre is no longer producing this piece anymore.  But you can still get it at some boutiques and authorized dealers.  The case and dial exhibit an excitingly elegant yet sobering design.  The crown is big enough to feel the feedback of the delicate mainspring.  This is a great watch, the movement is nearly identical to the Vacheron Constantin example; if it had some springs replaced, were built in Geneva Canton, and a higher standard of finishing, this watch would be eligible for the Geneva Seal! 

Notice the similarities and differences with the Vacheron Constantin 1003 caliber and the Jaeger-LeCoultre 849 caliber.  Photo Credit: Jaeger-LeCoultre.

Former Production:

Just 4.05 mm thick!  One of the thinnest watches in the world.  In Platinum.  Even the hands had to be installed abnormally carefully so they wouldn't hit the sapphire glass.  Photo Credit: Amanico.

Jaeger-LeCoultre Jubilee Master Ultra Thin Platinum.  I considered this the best timepiece of SIHH 2013.  It is an incredible value for a platinum watch!   It utilizes Jaeger-LeCoultre’s 849 caliber, a 1.85mm thin caliber that is made alongside Tourbillons and Minute Repeaters in the Grand Complications workshop. Most of these limited production timepieces were quickly sold in 2013 and 2014, but used examples pop up on the market from time to time.  Most are gently used as most buyers view this piece as a piece for special occasions.  The crown is small and difficult to wind but the whole package is incredibly special! 

The posterior of the ultra thin watch is covered in platinum which lends the watch a nice weight.  The movement is rather small relative to the case so I'm more pleased to see the platinum case.   Photo Credit: Amanico. 

Is it worthwhile to acquire an Extra Plate or Ultra Thin watch?  That’s really up to you and maybe if you attend a lot of dinner parties.  But for this watch collector who wants to sample a bit of everything, go to your local watch retailer and try on some Ultra Thin timepieces.  Many will find their inner Goldilocks stating it’s too thin.  But some will experience an enlightening moment and find it to be just right! 

well written Patrick...

 By: mahesh : February 13th, 2020-23:21
it never crossed my mind that there are no accuracy claims in Ultra thin models...

i happened to try few of them on wrist, esp. the JLC Jubilee & the VC Historique - within few minutes you've a doubt if the watch is still on the wrist (especially i like to feel the watch on the wrist).

thanks you !



 By: patrick_y : February 13th, 2020-23:48
Thank you Mahesh for the kind words.
I wouldn't say there are "no accuracy claims" as this really depends on the brand. For instance, JLC claims they have a very intensive 1000 hours test, but there is no accuracy standards claimed, even for thicker models.
Those watches you mentioned are definitely very thin and they disappear. Sometimes I find them "too thin" but they're definitely very rigid and solid timepieces. They feel well built.
Thank you again for commenting!

A collection is never complete without one axtra slim watch

 By: COUNT DE MONET : February 14th, 2020-01:04
I would say under 6 mm für the whole watch is already extra slim.
Rolex 3135 caliber is alone 6 mm, just to give an orientation.

Thank you for the enjoyable read!

Thank you Count!

 By: patrick_y : February 14th, 2020-08:29
I would agree with you on the 6mm, but I've been told by watchmakers at Piaget that it really starts to get supremely difficult when the movement is 2mm or under. That's when the case and movement team need to work heavily together to ensure the final product comes out correctly.

I used to consider the Patek Philippe 5119/3119/5196 to be ultra slim, but I was told that I was wrong. They're still very slim in my book!

A 2 mm and under movement is unbelieveable thin

 By: COUNT DE MONET : February 14th, 2020-11:31
Regarding Patek 5119/5196: my Ellipse 3738 J with the cal 240 is even thinner as the afore mentioned.
Like the current Ellipse it is the slimest watch Patek is offering.
Patek calls the 240 extra flat.

Patek's 240 caliber is my favorite!

 By: patrick_y : February 14th, 2020-13:33
I fell in love with Patek Philippe back when I was a teenager because of the 240 caliber.  It's sublime slimness and that micro rotor (admittedly my first time noticing a micro rotor) intrigued me and the high quality finishing finished me off. 

I always considered the 240 caliber to be an Ultra-slim watch.  And as far as automatics go, we're probably not wrong (although Piaget has some even slimmer automatics).  But as for manual winds, definitely has to be below 2mm. 

I really like the 240 caliber though; it's a great balance of practicality.  Slim enough, probably more accurate than an Ultra-slim watch, a reasonable power reserve, and overall more practical. 

Thanks for a very informative read.

 By: halkcb : February 14th, 2020-03:16
I have always enjoyed an ultra thin watch for its elegance and silhouette.
Not too sure of its accuracy ,as it lacks a second hand,but has been keeping time adequately for its purpose.

An old vacheron with its cal 1003

like the slimness of the case

An enjoyable watch to wear

1003! That is a nice watch with a superb movement!

 By: patrick_y : February 14th, 2020-08:31
The more I get to understand this watch, the more I realize how special it is. You have a very special watch on your wrist! Do you use yours daily or more for special occasions?

Definitely not a daily wear---for dress occasion usually but it's enjoyed nonetheless [nt]

 By: halkcb : February 14th, 2020-08:37
No message body

That's wonderful.

 By: patrick_y : February 14th, 2020-08:50
A wonderful watch. And I'm glad you enjoy it! Now I just have to find some special occasions to wear ultra thins!

O I like this one [nt]

 By: Jurry : February 15th, 2020-05:35
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Thanks for looking. [nt]

 By: halkcb : February 15th, 2020-06:17
No message body

Good review

 By: Jurry : February 14th, 2020-03:17

Thanks for posting your review. It’s comprehensive, clear, and all in all nice summary.

Obviously there are many manufacturers who claim they produce ultra plate pieces and some of them actually do produce ultra thin.

Although I like it when such a watch slides easily under your business shirt, I would be worried all day long for damages as the movement is so much more fragile.


Thank you Jurry!

 By: patrick_y : February 14th, 2020-08:33
I agree, I'm a little worried about the fragility. As a special occasion watch for dinner parties, I suppose I'll be okay. But as a daily then I'd be more concerned. For a daily, I'd step into a "slim" but not ultra-slim watch like a Vacheron Constantin 4400 caliber or a Patek Philippe 240 caliber. They're still slim, but not ultra-slim and not as fragile.

😀👍👍 [nt]

 By: Jurry : February 14th, 2020-13:38
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I suppose weird things happen at formal events too...

 By: patrick_y : February 14th, 2020-13:42
I suppose when one is in their tuxedo weird things can happen... Runaway bride, wedding cake that rolls into a seated crowd creating panic stampede, dancing, and ice sculpture collapsing creating stampede and panic. These are all potential ways to damage a watch that is normally only worn for formal occasions. I heard of a bear once crashing a wedding party in the woods. But I don't think people were wearing tuxedos for that wedding party.  Hmm, a lot can happen at formal parties, especially weddings! 

For me, the only downside of my accurate & beautiful (and, so I was tole, durable) Audemars Piguet 2003 was finding a watchmaker competent to service it. [nt]

 By: kjkt3 : February 14th, 2020-03:27
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Beautiful Watch Movement!

 By: patrick_y : February 14th, 2020-08:37
Similar movement as the Vacheron Constantin 1003 and Jaeger-leCoultre 849!
That's a very realistic problem!

Well done and extremely informative. Thank you for the time you took to write this article. [nt]

 By: aperna : February 14th, 2020-04:09
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Thank you for reading and your generous comment! [nt]

 By: patrick_y : February 14th, 2020-08:37
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A few of my thin pieces

 By: cazalea : February 14th, 2020-05:29
A few are ultra, a few are thin. I think if the watch is thinner than the crown height OR thinner than its strap, it's ultra-thin.
Thanks for the article.


I don't have one, but my favorite is the Piaget (photo from Nilo)

So far I have resisted, but this Citizen eco-drive is the world's thinnest quartz / solar watch

Those are some thin pieces!

 By: patrick_y : February 14th, 2020-08:40
I've always liked those gold bark finished bracelets on those Vacheron Constantin timepieces. Gorgeous timepieces, but I just can't stand how one has to "cut the bracelet" to fit their wrists. I fear I wouldn't be able to wear the watch if I gained girth on my forearms.
That Credor is striking and definitely not something we see often. Thanks for sharing that!

Man, that Piaget and that Vacheron are both superb! [nt]

 By: LS : February 14th, 2020-18:05
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”Please allow me to introduce myself”

 By: Pelle_thorstenson : February 14th, 2020-06:31
Being a newcomer on this site I must start buy saying how impressed I am by the great knowledge I have seen here. Many writers also bring their thoughts forward with an elegant sense of humour. When I read about slim watches to me it was an illustration of this and I realise my limited knowledge compared to most of you. However ”I’m no school boy and I know what I like”! (M Jagger) which brings to why I am here. 

My plan is to buy a PP and wear it for a couple of years. After that I will give it to my son and ask him to pass it on to his boy when he turns 18. (You merley look after......) The ones I am looking more closely at are 5327 (probably to expensive), 5205 and 5396 but I will not feel ashamed when learn from the things you write. Bon weekend 

Welcome Pelle!

 By: patrick_y : February 14th, 2020-08:43
Thank you for your kind words Pelle! You'll find many of the moderators and our members are extremely knowledgeable about the subject matter, its history, and the back stories of brands and their collaborations. A lot of the Swiss watch industry used to work together quite closely co-developing technologies, nowadays this seems to happen less and less.

If you're considering those fine Patek Philippe models, I would highly encourage you to consider the Patek Philippe 5140 and Vacheron Constantin's perpetual calendars as well. Those are top notch pieces that will be great for your son when he is ready to take the helm.

Thanks Patrick

 By: Pelle_thorstenson : February 14th, 2020-10:24
If I told you that this is your lucky day and you have won either one of the 3 I mention or the 5140 which one would you take - to keep and not to sell?
When I hold a perpetual it gives me a feeling that is difficult to describe versus an annual watch. However I think I pay a lot for that feeling and I do believe I pay even more when it comes to service cost. According to your opinion is the perpetual worth it?

You have to go your own way...

 By: patrick_y : February 14th, 2020-11:11
I was once considering the Patek 5396G back when it had the sector dial.  I ended up getting a different Patek Philippe timepiece instead.  One that was thinner.  The 5396G was too polished, had sharp edges, and was a little too thick.  I like the 5205G but I find it a little weird.  It's definitely cool, but the pierced lugs is a little strange at the same time.  If I were considering the 5205G, I'd consider the 5235G as well. 

A friend of mine got the 5396G and loved it, but was a little sad when he got a small nick on the sharp edge of the case.  He eventually upgraded to a 5140J and loves the watch.  He was split between the 5159G and the 5140J.  Ended up with the 5140J and loves it.  He loves the slimness of the timepiece.  He now wants a 5140G.  He acquired a 5140R with brown dial for his spouse. 

I'm personally a big fan of the 5140, although I don't own one.  I would definitely like to get one.  This is a great watch and performs dual function as a dress watch and as a daily watch.  The thinness and lack of a seconds hand gives it formality (a small seconds hand is okay, but a large sweeping seconds hand is considered too much movement for formal situations). 

The friend above says the one thing he doesn't like about his 5140 is the lack of a seconds hand means he can't tell if the watch is "alive" or not.  A very minor problem to him.  He finds he can't travel with the watch because you can't adjust the watch without fear of ruining the synchronization of the calendar mechanism, so he finds that he travels with his 5396G. 

I'd get the 5140 if I could find one.  Used, they're not terrible in price.  And don't limit yourself to the big famous brands like Patek Philippe and Vacheron Constantin.  True, they're the two most famous brands, but keep an eye on Lange as well.  Great watches.  Noticeably thicker though. 

New thoughts

 By: Pelle_thorstenson : February 15th, 2020-00:28
Very interesting to read your reply Patrick. I am going to give some further thinking on how I like to see minutes shown on my watch. Not a thing to take as lightly as I have in the past. The 5140 has become a strong contender on my list. I do like PP myself and I like it also for the feeling of long term sustainability it gives me when I pass it on to the coming generations. Grazie!

You're welcome!

 By: patrick_y : February 15th, 2020-09:34
If you like the 5140, check out the 3940.  Same movement.  3940 has a slightly smaller case.  I personally prefer the 5140 over the 3940, mainly because I'm starting to like bigger watches.  I'd love to own a 5140J or 5140G someday. 
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