The Rolex Metals Series: 18K Rolesor

If you could sum up Rolex’s mission, from the very beginning, it has been to manufacture watches which are simultaneously highly luxurious and extremely robust.

The perfect visual representation they found to encapsulate both of those qualities is in their bimetal combination known as Rolesor—partnering the opulence of gold with the toughest stainless steel.

It is a process the brand originally patented in 1933, but it wasn’t until the late 40s that it found its first application, and spiritual home, on the Datejust. However, the look proved to be ahead of its time and didn’t catch on in the early years. Today though, there are Rolesor examples of many of the company’s watches, even among those most potent symbols of masculinity such as the Sea-Dweller.

The grades of both metals used in the Rolesor construction have progressed over time. The steel has graduated from the 316L, used by practically the entire horology industry, to 904L, a more corrosion resistant option ideal for a hardworking timepiece.

As for the gold, Rolex has employed various grades of the precious metal during their run. The lower categories were found mainly in the American market, with 14K being the purest that could legally be sold in the U.S. between 1934 and 1974. In their formative years, the manufacture used 9K as well.

18K was reserved for other parts of the world, a more pricey and somewhat softer metal.

When the import restrictions were lifted, Rolex set about the long process of retiring the lesser alloys of gold, although you could still find 14K watches as recently as the 1990s.

It was all part of their transformation from being merely the makers of the finest timepieces in the business, into the ultimate lifestyle brand. With the invention of quartz technology, the traditional watchmaking fraternity were forced to remarket themselves more as purveyors of status symbols, trading on their artistry and heritage rather than price and accuracy; a battle they couldn’t hope to win against the new electronics.

Hand in hand with that went a commitment to only use the best materials available, and so today Rolex crafts their models exclusively from 18K, whether all-gold or in Rolesor.

Below, we explore the brand’s use of 18K gold in their steel and gold watches.

What is 18K Gold?

Pure gold is rarely used in jewelry making. Known as 24K (for Karat), it is too soft and easily scratched to be practical.

To lend the material extra strength it is alloyed with other metals, which vary depending on the color of gold required, and in different proportions.

So for 18K, just about the highest gold content in watchmaking, the gold itself makes up about 75% of the whole. As for the rest; for yellow gold, it is blended with silver and copper, with traces of zinc. With white gold, a mixture of silver and palladium, or else nickel, is used and often plated with rhodium (although Rolex does not) and for rose gold, just copper is added (along with something like 2% platinum in Rolex’s case to give the color extra longevity).

Because of the high concentrations of the precious metal, 18K gold is the most expensive grade employed by the horology industry, obviously reflected in the prices of the watches. The weight can also come as something of a surprise as well, with the models being noticeably heavy.

Rolesor: Best of Both Worlds?

Rolex’s bimetal invention has a number of things working in its favor when compared to a solid gold watch.

There is an inherent increase in durability, with the majority of the watch made from stainless steel. They are also cheaper, sometimes significantly cheaper, than an all-gold piece. Bizarrely, depending on the exact model, you will even find they can be less expensive than an entirely stainless steel watch on the preowned market too. The most accessible Daytona, for instance, is currently the ref. 16523 in yellow Rolesor, as demand for the all-steel sports Rolexes continues to be immense.

But perhaps more than anything, they have a particularly distinctive look which lends them a great deal of flexibility. Not as grandiose as all-gold, nor as utilitarian as steel, they are the very definition of a halfway point between the two, and so rarely look out of place in any surroundings.

In addition, the different colors of gold the brand combines with the steel gives each one its own personality. Currently, Rolex’s Everose Rolesor is proving especially popular, providing a visual that has a pleasing warmth. Yellow Rolesor is the most traditional, and is the aesthetic which drifts in and out of fashion the most. And white Rolesor is the most neutral, with the tones of the gold and steel similar at first glance before the subtle gleam of the precious metal shines through. Interestingly, with the white Rolesor pieces, Rolex only uses the gold on the bezel, with the rest of the watch all stainless steel. For the other two types, the precious metal forms the bezel, winding crown and central bracelet links.

There have been many examples of all three types over the years, and below we look at each one’s individual reference numbers and approximate dates of production.

Date

Datejust

Datejust II

Daytona

GMT-Master

GMT-Master II

Oysterquartz Datejust

Oyster Perpetual

Sea-Dweller

Sky-Dweller

Submariner (Date)

Yacht-Master

Yacht-Master II

* Approximate years of production

— Featured Photo Credit: BeckerTime’s Archive.