The most common and popular material in watchmaking is 316L Stainless Steel. It is of a surgical grade, hypoallergenic and capable of being finished in multiple ways. It can also be refinished many times without suffering significant deformation.
The “gold standard” of steel within the industry, however, is 904L, which is a type of steel used almost exclusively by Rolex. 904L is said to be more resistant to corrosion, and able to hold a higher polish compared to 316L. These capabilities have led more and more brands to start using this material, in an attempt to disrupt Rolex’s unique selling point.
Realistically, however, it is unlikely wearers would notice much corrosion on a 316L stainless steel watch, as the difference between the two types of steel would take a remarkable environment to manifest.
Yellow gold was almost certainly your father or grandfather's idea of what a real watch should be made of. This classic material is now making a subtle return to popularity, with some differences. Most high-end yellow gold watches today are made from 18 karat gold (75% pure), instead of the 9 karat gold that was popular a generation or two ago. Yellow gold is also the purest color of all golds, which has the added benefit of making it the easiest to maintain.
Some brands have experimented with new gold alloys in an attempt to revive a somewhat out-of-date material. Perhaps the most successful on this front has been Hublot, which has managed to create both “King Gold” and “Magic Gold." The latter is fused with carbon particles and almost impossible to scratch.
The commonness of gold-colored coating such as PVD (powder vapor deposition) has risen as many entry-level luxury brands attempt to a “democratization of luxury." This is a cost-effective and relatively durable way to achieve the same kind of look as genuine gold. Be warned, though, it doesn’t take that trained an eye to spot the difference between a PVD coating and the real thing. Genuine yellow gold has a warmth and depth to it that is really stark when placed next to an imitation.
In the 1990s, it was rare to see rose gold featured in watchmaking. Today that is an entirely different story, as the warmer, pinkish shade of gold has boomed into popularity. Despite yellow gold’s slight return, red/rose/pink gold doesn’t seem to be under any real threat.
The reddish hue of this metal is created by copper in the alloy. If you increase the amount of copper, you’ll achieve a redder result. The Karat weight of rose gold is still decided by the amount of pure gold in the mix. The most common ratio is 75% gold to 25% copper by mass, which would carry an 18 karat rating. This is normally the highest karat you would expect to find, as there is no such thing as pure rose gold due to the copper that gives it its distinctive color.
One of rose gold’s benefits is that the copper in the alloy makes it more durable than its yellow or white gold counterparts. However, the copper means this is not a hypoallergenic metal, so may cause a slight irritation to some skin types.
Another common material in watchmaking is white gold, which has the same look as steel but gives the wearer the knowledge that they are wearing something much more luxurious. While it normally only makes an appearance in Haute Horlogerie, it has a large following of those who enjoy the concept of stealth luxury.
As such, white gold has exploded in popularity in both watchmaking and other industries. One other advantage is that white gold is alloyed with tougher metals than yellow gold, which makes it more long-lasting. It is also far easier to coordinate your wristwatch with contemporary jewelry.