What Is A Sigma Dial And Why It Is Important

When it comes to antique watches, tiny details are very important. In fact, they are basically everything. When evaluating the dial’s originality, the details become a double-edged sword, as any replacement or modification of the dial will have a great impact on the overall value of the watch. This explains the problems of watches made from the 1970s with the strange round small marks on the sides of the dials ‘Swiss’ or ‘Swiss Made’. These small marks are actually lowercase Greek letters Sigma (Sigma, Sigma), so dials carrying this mark are also appropriately called ‘Sigma Dials’. The problem is that most of the information we usually see about sigma dials is wrong and it’s easy to see. So I decided to dig deeper and try to figure out the exact time and reasons behind the sigma dial. The story is more interesting than I expected.

An ad from APRIOR highlights that apart from Swiss watches being precise and reliable, gold parts are also valuable

   The first rumor about sigma dials: these small letters are mandatory markings, which were suddenly added by watchmaking brands in the early 1970s. This statement is of course impractical, because Sigma is an independent choice of watchmaking brands and a sign of identification. More specifically, it is the exclusive logo of several brands that join the promotion of the gold watch industry association APRIOR (l’Association pour la Promotion Industrielle de l’Or), which explains why not all brands have Sigma dials Watch. The association was led by the Swiss Watch Industry Federation and was established in 1973 with the clear purpose of promoting practical gold parts for watches and increasing the intrinsic value of mechanical watches.

APRIOR’s statement clearly describes the purpose of the sigma dial

   I believe you must remember the situation facing the Swiss watch industry at that time: the global economy was sad and dismal, and under the impact of the quartz wave, mechanical technology was about to fall behind. Want to emphasize the deep value of old mechanical watches, is there any better way than mentioning parts with intrinsic value? The logic here may sound a bit unclear at first glance, but we have to take into account that the price of gold soared in the 1970s, and the price of gold tripled between 1970 and 1974. The sigma symbol proves that the hands and hour markers of the watch are made of solid gold. APRIOR emphasized in its marketing campaign: ‘Buying a watch with the Sigma logo is a reliable investment.’

A Rolex Daytona Ref.6263 produced in 1974 with two lowercase sigma on the sides of ‘Swiss’

   In the end, even if it’s not entirely convincing, at least the Sigma initiative sounds reasonable. However, the sigma initiative may not be as innovative as APRIOR claims, because it is very similar to the ‘OM’ logo used by Omega in the mid 1950s (and you can see the Apollo XI Ref.BA, the speedmaster launched by Omega at the same time as APRIOR was founded 145.022-69 watch). Omega did choose to use ‘OM’ to mark the dial made of pure gold. This mark does not involve hands and time stamps, but it is very close to Sigma in concept. Of course, we may never find out that the ‘OM’ mark affects APRIOR. evidence of.

Omega Speedmaster Apollo XI gold watch clearly shows the unique ‘OM’ mark on the bottom of the dial

   Although APRIOR was officially established in 1973 (its charter was drafted in 1972), the Sigma symbol was registered as a trademark as early as August 1971. Many sources set the date of the first sigma dial in 1973. If we use the watch (usually the best source of evidence) as evidence, we can prove that the origin of 1973 is completely wrong. You can find a large number of Rolex watches from the 1970 series with the serial number and the Sigma logo. This means that the appearance of sigma dials not only predates the establishment of APRIOR in 1973, but also before the sigma mark is registered. .

Rolex used Sigma dials before 1973, as evidenced by this 1972 Rolex Datejust Ref.1603 dial watch

   If we review the trademark again, we will find that it has been continuously updated until 2003, and APRIOR officially launched the stage of history four years later (2007). As far as Rolex is concerned, the brand stopped using Sigma dials in the late 1970s, a little later than what is commonly thought of in 1975. The beauty here is that there are a large number of Rolex antique watches on the market, allowing us to easily trace the age of Sigma dials. Unfortunately, Rolex alone cannot fully understand the secrets of the sigma dial. Historically, many other brands have joined APRIOR (five to nine members at any given time), and manufacturers that supply movements such as Stern and Singer also produce sigma dials. Apart from Rolex, the most famous brands among them are Patek Philippe, Vacheron Constantin and IWC.

In this advertisement, the Sigma logo on the dial of Patek Philippe Nautilus Ref. 3700 stainless steel watch can be clearly seen

   Just a little observation is enough to clearly understand the sigma dials used by many famous dials produced in the 1970s, such as Patek Philippe Nautilus and Ellipse d’ Or, Vacheron Constantin 222 (square), and IWC engineers. Interestingly, like Rolex watches, these models are not all equipped with a solid gold case; in many cases, a stainless steel watch can also be decorated with the Sigma symbol, just because it is equipped with solid gold hands and hour markers.

Patek Philippe Ref. 3587 (with Beta 21 movement) is also often equipped with a sigma dial

   Through these brands, we can dig deeper into the timeline of sigma dials, because whether it is Patek Philippe Nautilus or Vacheron Constantin, the sigma dials are still applied until the 1990s. This key piece of information also allows us to clarify another rumor about sigma dials, which are by no means replacement dials, but genuine, as long as these watches meet the timeline of sigma dials for specific brand series. In principle, I would like to give a clear deadline for applying sigma dials, but everything is still to be determined. All I can find is the last sigma dial, which is equipped in the watch produced in 2000, but note that the dial is manufactured in batches. The production of the watch in 2000 does not mean that the dial is also the same, the latter may be produced earlier.

This 1997 Vacheron Constantin watch is still equipped with a sigma dial

   Despite the uncertainty of the deadline, I firmly believe that knowing the ins and outs of the sigma dial and knowing where to see (and where not to see) has practical significance. For example, watches produced in the 1960s with Sigma dials are certainly not the original configuration. Looking back at the history of sigma dials, we must praise APRIOR’s initiative, but at the same time we must be honest with the true story of sigma dials: it has never been a comprehensive measure envisaged for the entire watchmaking industry, nor has it helped prevent the 1970s Quartz crisis.

The second page of the APRIOR statement also mentions the use of sigma symbols for cases, bracelets and even labels; the investigation is certainly not over
   This enduring issue is related to the most basic assumption that end customers really value knowing whether some parts of their watches are made of precious metals. In my opinion, the above assumption seems flawed, because this type of knowledge does not carry the emotional factors expected by APRIOR, and a large part of customers may not even know the existence of the sigma symbol. After all, no one knows the purpose of selling a watch when the scrap is sold after smelting; What is the net weight of pure gold with three hands and twelve hour markers?
   This explains two things: why sigma dials have not left a lot of lasting marks in the industry, and why focusing on the attractiveness of craftsmanship is a wise choice for the watchmaking industry to seek long-term development. There is another deeper implication here, that the world of antique watches is complex, and for any given subject, there are many versions of the story, including many inferior information. All in all, it’s worth doing a little extra research.