Quality materials make a great timepiece and stainless steel is the top choice. It’s a relatively affordable metal that offers excellent strength compared to its price to produce it.

Stainless steel differs from regular steel as it doesn’t oxidize due to its make-up of at least 10.5% of chromium, carbon, and iron. Its anti-corrosive qualities make this material ideal for luxury watches.

In day-to-day life, 304 is the most commonly used type of stainless steel. Widely used for making household items, such as pipes and cookware, it’s the most accessible type of stainless steel and relatively low in price. This material also contains more carbon, making it darker in colour versus the other stainless steel options.

While some low-end watches use this 304 stainless steel, its more prone to corrosion than 316L and 904L, making it susceptible to damage from sweat and saltwater over time.

Also known as surgical grade steel, 316L is the most commonly used type of stainless steel in the watch industry. The majority of steel watches use this type over 304 because it is significantly more corrosion resistant.

The “L” in 316L denotes a lower carbon content than 316 stainless steel, making it more stable in high temperatures and anti-magnetic than its lower grade comparable. Its price to property ratio is also great for manufacturing.

The ultra premium 904L is a superior alloy with incredibly high corrosion resistance, but is much harder to process and extremely expensive.

It’s typically used for building piping systems, such as heat and pollution equipment, because of its high resistance to acids. Type 904L contains more chromium, molybdenum and nickel, which makes it more corrosion resistant than 316L. The colour is also slightly cooler and whiter, thanks to the lower carbon content and higher chromium content.

While 316L is more than enough for most luxury watchmaking, brands like Rolex have marketed 904L steel watches as the best as they have invested significant resources in processing the material.