Model 5402 Dial Variants

The dial of Model 5402 combines two complementary geometrical shapes: the circle and the square. Curved and straight lines, straightness and fluidity; or more symbolically rigorous discipline and flexibility. On the one hand, the circular shape of the dial is highlighted by the 12 applied hour-markers, finely punctuated by the minute markers and, above all, by the tens of thousands of tiny diamond shapes carved into concentric circles.

On the other hand, the square shape is expressed through the hundreds of small, flattened pyramids aligned in a checkerboard pattern, crisscrossed by the same number of horizontal and vertical lines, like the streets of a city. This verticality is reinforced by the axis between the double 12 o'clock hour-marker and the AP monogram at 6 o'clock, while the horizontality is based on the AUDEMARS PIGUET signature, accentuated by the AUTOMATIC indication and the date window at 3 o'clock. It is also worth noting that the latter creates an asymmetrical effect because, as is widely acknowledged, a harmoniously pleasing face is always slightly asymmetrical.

This subtle combination of geometrical shapes takes on its full meaning when viewed in relation to the Royal Oak's faceted case, which also plays with shapes. The bezel is indeed a rounded octagon and the monocoque case is shaped like a tonneau (barrel). Thus, like the watch case and perhaps even more so, the dial of the Royal Oak is designed to reflect light, superimposing several patterns featuring different geometries to create infinitely varied moiré effects.

The Stern archive indicates that the guilloché pattern is labelled 'T21', an abbreviation of ‘Tapisserie No. 21'. The name Tapisserie deserves a small aside. The watchmaking world, and more particularly that of collectors, has become accustomed to using the term Tapisserie to describe the Royal Oak's dial motifs. This metonymy results from the fame of the model. As stated by the website of the Fondation de la Haute Horlogerie (FHH), tapisserie means "a pattern of repetitive motifs, similar to a tapestry. A die of this motif guides the movement of the tool on a specially adapted rose engine.”

Most of the Tapisserie designs in the Stern archive are floral or arabesque motifs. The T21 pattern, on the other hand, is loosely inspired by the Clous de Paris guilloché pattern that can be traced back to at least the 18^th century and consists of small pyramids with square bases. Adopted for Model 5402, the T21 motif became widespread in the Royal Oak collection from 1976 onwards, particularly on Models 8638, 4100, etc. At the beginning of the 21^st century, its name changed to Petite Tapisserie, in contrast to a larger variant created in 1999, known as Grande Tapisserie, which replaced it within a few years. In 2012, for the Royal Oak’s 40^th anniversary, the Petite Tapisserie made a comeback on Model 15202 which also bears the AP monogram at 6 o'clock.

Between each of the pyramids, and partially on top of them, an extremely fine dotted line plays with the light. Marc Ferland explains: "We fix the dial on the guilloché machine and it then begins spinning on its axis.” And as it turns, the sharpened tip of a burin makes small holes without ever going through the metal, like a woodpecker digging its nest. In one complete turn, it enters the material 339.5 times and comes within an 11^th of a millimetre of the dial centre. For a dial with a 28 mm diameter, it takes 154 turns to cover the entire metal surface with over 50,000 microscopic holes.

But if you walk into Marc Ferland's workshop and talk to him about "little dots", he immediately responds: "They're not dots, they're diamond shapes! If they were round, the dial wouldn't shine.” Each diamond shape has four small inner faces that reflect the light. More importantly, because the number of diamonds is the same for each turn, the closer the circles get to the dial centre, the closer the holes also get. "That's when you'll see new curved lines appear, formed by the ever-tighter pattern”, enthuses Marc Ferland, who completes the picture with technical explanations that are as passionately detailed as they are abstruse for the uninitiated, punctuated by terms such as "rosettes", "cam", "ideal angle" and "pointer."

Hidden from view and from the light, the back of the dial is not destined for observation, yet it contains information of interest to both collectors and watchmakers.

On the one hand, its colour remains closer to the original. In this respect, the Audemars Piguet Heritage team was surprised to discover slightly purplish reflections, which suggest that in 1972, some dials must have had a very different colour from what we usually imagine.

On the other hand, the back of the dial is engraved. The reference book written by Helmut Crott entitled Le cadran, visage de la montre-bracelet au 20e siècle unlocks the code: "the 6 designates the Audemars Piguet customer, while the star corresponds to the Stern Frères hallmark at the time.” The following number represents the order number, as confirmed by the Audemars Piguet archives. On the other hand, Helmut Crott indicates that 4N (appearing here as "N4") refers to the colour of 4N gold, but this information is not corroborated by sources, since analysis conducted by the Audemars Piguet laboratory has shown that the plates of the first Royal Oak dials are made from a variety of bronze called Chrysoscale.

Finally, the watchmaker will be able to check at a glance if the dial has been refurbished in the course of its history, by examining the colour, the finish, as well as the feet of the hour-markers and the AP monogram. Redoing a dial colour entails removing and then refitting the applied elements (hour-markers and logo) and such an operation always leaves traces.

Collectors have long since known that while the first generation of 5402ST has the AP monogram at 6 o'clock, many examples are equipped with later dials featuring an AP logo at 12 o’clock. Here again, while the archives do not document the reason for this change, watchmakers’ memories fill that gap. Restorers explain how, after several years, certain watch hands begin to rub or even bump into the applied logo, sometimes to the point of stopping the watch. Within this context is it important to remember that the distance between the hand and the logo is five to ten hundredths of a millimetre! Some artisans have humorously noted that it was almost as hard to get the hand through this narrow passage as for a camel to pass through the eye of a needle.

To solve the problem, Customer Service watchmakers initially used to bend the hands manually, a tricky operation that consisted of creating two tiny, inverted Z-shaped bends to raise the two hands high enough to pass without touching either the logo or the glass and without touching each other. However, in order to provide a permanent solution, Audemars Piguet decided on February 24, 1977 to move the logo to 12 o’clock, so as to leave sufficient space for the movement of the hours hand. The next day, a first order for 210 "new execution" dials was sent to Stern.

This decision might lead one to assume that from spring 1977 onwards, all new Royal Oak 5402 watches featured the new dial with monogram at 12 o'clock. This is not the case and to understand why, it is important to know that between 1972 and the last order of March 1977, Audemars Piguet ordered 4,336 of the 5402 dials, whereas during that same period the company sold 2,978 Royal Oak 5402 watches. That meant that by the spring of 1977, over 1,200 dials with the 6 o’clock monogram were still in stock!

The archives documenting the dial change reveal little and do not for example mention when the first watch with an AP monogram at 12 o'clock was produced or when the last new 5402 with the monogram at 6 o'clock was delivered. They remain equally silent regarding the timepieces on which dials with the monogram at 6 o’clock were replaced by “12 o’clock” variants. Worse still, they do not even reveal whether the two variants ever coexisted.

As is often the case, historians have to be ingenious and build hypotheses. Let's first take a look at the big numbers. From 1971 to 1990, Audemars Piguet ordered a total of 6,983 dials for Model 5402, of which 5,189 were blue, 1,548 slate grey and 246 gold-toned (also referred to as "brown"). Of these, at least 62% had the AP monogram at 6 o'clock. More importantly, Audemars Piguet ordered 911 more dials than the number of watches sold! This implies that a maximum of 15% of 5402 watches could potentially have had their dials replaced in the Audemars Piguet workshops.

Let us focus exclusively on the Bleu nuit, Nuage 50 variant with white gold hour-markers, intended for the stainless steel Royal Oak 5402ST. Between 1971 and 1990, the company ordered a total of 4,992 dials, of which at least 4,085 have an AP monogram at 6 o'clock – implying that a maximum of 907 had it in the 12 o’clock position. In an amusing little exercise, assuming that each of the last 907 Royal Oak watches sold were equipped with a dial bearing a logo at 12 o'clock, the dial change would have taken place in the spring of 1978, i.e. around number 1500 of the C series (see article on 5402 serial numbers). This is unlikely, since we know that many 12 o'clock dials were used to replace earlier variants.

Another theoretical exercise, this time in reverse. If Audemars Piguet had used the 4,085 dials with the AP monogram at 6 o'clock available in stock before starting to use the dials with AP at 12 o'clock, the watchmakers would have started to equip 5402 watches with AP at 12 o'clock dials in November 1981, corresponding to the end of the D series. Only 219 new watches would have been fitted with this dial at the time of their first sale. This hypothesis is even more improbable because it implies that Audemars Piguet would have waited more than three years between the order of the first “6 o'clock” dials and their first use! The truth probably lies somewhere between these two extremes, between February 1977 and November 1981.

In conclusion: if it was seamless, the change probably took place towards the end of 1978. If it was slow, which is more likely, the two variants probably coexisted between the summer of 1977 and the summer of 1979. The only certainty, based on dial orders, is that of the 4,304 examples of the 5402ST, a maximum of 16% have the AP monogram at 12 o’clock.

A distant descendant of the watchmaking guild hallmarks of the 17^th century, the Swiss Made indication guarantees the quality of watches bearing it. Protected by an ordinance since 1971, it complements the numbers engraved on the watches and their movements; the multiple hallmarks (precious material, dial-maker, case-maker, bracelet, etc.); the engravings relating to the number of jewels; and of course the dial signature.

On Audemars Piguet dials, the indication of origin gradually established itself. In the 19^th century, "Le Brassus" occasionally appeared beneath the trademark. From the 1930s to the late 1960s, this same position was often occupied by the "Genève" toponym, a reminder that Audemars Piguet had a complications workshop in this city. As for the name SWISS appearing in small letters below the hour-marker at 6 o'clock, it progressively asserted itself from the 1920s onwards. By the 1970s, it had become the norm – so much so that all the first Royal Oak watches were fitted with it.

Over time, dials develop a patina. They can become scratched and oxidised. The dial restorers then suggest “refurbishing” them, an operation which consists in dismantling the appliques, removing the paint, the varnish and the colour, as well as the oxidation. The dial is then given a facelift that involves redoing the electroplating, transfers and repositioning the refurbished hour-markers, while the guilloché work on the Tapisserie pattern is never touched up.

While the "refurbishment operations" comply with the original techniques and aesthetics, they sometimes show traces of the period in which they were performed. For example, the SWISS indication that appeared below the 6 o’clock hour-marker until around 1985 was replaced from that date onwards (approximately) by a SWISS MADE indication. This minor change, to which contemporaries probably did not attach any particular importance, has become an important criterion for collectors in the valuation of watches, as has the position of the applied AP monogram.

The reason is simple. When a dial bears the indication "SWISS MADE", it means that it was either completed or refreshed after the mid-1980s. The Audemars Piguet Heritage team has scoured the archives and tapped former employees’ memories at length in order to find the reason for this change. It seems to be simply aesthetic: the two words SWISS and MADE on either side of the hour-markers at 6 o’clock help balance the dial.

It should also be noted that the SWISS MADE indication may have appeared on 5402 watches when they were first marketed, as the last 133 examples were sold between 1985 and 2002.

In 1977, the Royal Oak 5402 was interpreted for the first time in yellow gold, white gold and in a two-tone version. The guilloché dials followed the trend by offering a variety of colours, changing the material of the monogram and the hour-markers and even replacing the latter with diamonds.

Slate Grey Dials

Between February 1977 and September 1990, 1,548 "slate grey" dials were ordered to equip the two-tone 5402SA model. At least 220 of these had an AP monogram at 6 o'clock and at least 980 at 12 o’clock. The dial colour recalled the stainless steel of the case and bracelet, while the yellow gold hour-markers echoed the gold of the bezel and the studs. It is worth noting that while the Tapisserie pattern is the most emblematic, dials without this decoration emerged during the late 1970s in different colour variants as presented here.

Brown (or Gilded) Dials

Produced in a run of 740, Model 5402BA most often featured blue dials punctuated by yellow gold hour-markers. However, this model was also equipped with 146 gilded dials, including 25 with the AP monogram at 6 o'clock, 76 at 12 o’clock and 45 whose position is not specified in the archives. It should be noted that gilded variants with AP at 6 o'clock are extremely rare. No examples have been received by the AP Customer Service since 2000.

Gemset Dials

The archives record 23 orders for dials with diamond hour-markers. Blue, gilded or slate grey, with square or round studs, intended for Model 5402 or its 4187 gemset derivative, they revive the tradition of very small series or even one-of-a-kind models.

The dial of the first Royal Oak watches is a masterpiece of technical and aesthetic design that can be admired on several levels. From a distance, its moiré reflections play with the light while maintaining perfect legibility of the time. Viewed at close-hand, hundreds of small square pyramids with truncated tops (some view them as chocolate squares) are juxtaposed in a checkerboard pattern that accentuates the watch's horizontal and vertical lines. When seen under a microscope, the dial becomes a landscape punctuated by tens of thousands of diamond shapes that sometimes overlap and create complex curves.

Interpreted over the last 50 years in countless variants, the Tapisserie pattern has become one of the essential codes of the Royal Oak: larger or smaller, evolving, radiating, etc. This omnipresence should however not obscure the fact that – as early as the late 1970s – the Royal Oak also featured more classical dials without guilloché motifs, one of the most significant being that of the first Royal Oak Perpetual Calendar, Model 5554 released in 1984.

Editorial board: Audemars Piguet Heritage team, Le Brassus

First publication: 15 March 2022