1. Stainless steel
The most common used alloy both in industrial objects and ordinary daily wearings.
Discovered in 1924 and developed since then, appraised for low price, wide suitability and easy shaping.
Now, generally, just generally. 304 steel is the most common of the common. Other than watches, 304 is in pretty much every metal crafts in your daily life.
Next level we have 316L, THE "Food Grade Metal", THE "Surgical Metal". Basically bumping up the percentage of Chromium and Nickel, from 304's 20% and 10%.
Also throw in some Molybdenum, taking out more carbon. Hence the L for low carbon. Whole formula makes it more corrosion and magnetism resistant. Not mention the normal wear and tear.
And here, that's why most demanding watches chose to use. i.e diving watches, pilot watches.
The top level of stainless steel judging from pure material perspective is 904L.
Why only from the material view? It is indeed a great material, enhanced in corrosion resistant mainly compared to 316L.
But it's expensive to acquire and the double edge sword of toughness makes it also hard to process.
We got to give it to Rolex, for changing their whole manufacturing line just to adjust to 904L steel.
904L also nicknamed as the "Rolex Steel" for they are the only brand using it to all series.
Makes their watches truly amphibious, casual wear and hardcore diving.
2. Titanium / Titanium Alloy
A lightweight, tough, heat-resistant, cold-resistant metal with a melting point of 1,675 degrees Celsius.
In room temperature, a very thin oxide protective coating will formed on the surface.
Which provide strong acid and exhibits extremely high corrosion resistance and rust resistance.
But due to natural attributes of Titanium, it's easy to leave scratches and show a dimmer look of silver.
Titanium alloys are based on titanium and added to other elements.
There are two kinds of homomorphous crystals of titanium,
below 882 °C is a close-packed hexagonal structure α-titanium, and above 882 °C is a body-centered cubic β-titanium.
Being Titanium alloy, it adsorb the best of both world. Incredible strength and corrosion resistant.
3. Porcelain / Ceramic
The manufacturing process of high-tech ceramic is to use extremely fine zirconia powder. After the powder is injected into the mold with high pressure.
Will put into furnace with a temperature of 1450 degree Celsius to form the parts you saw. After that, polished with diamond powder.
Pros: The surface is very smooth, extremely wear-resistant, stable in physical properties, resistant to acid and alkali, non-discoloring and decolorizing, light in weight, and pollution-free.
Cons: It is easy to break, and it is more afraid of falling and bumping. Repairing requires entire replacement of broken part.
4. Brass / Bronze
Watch having two faces or multiple faces one would say. That's the new kid on the block this decade.
Unique properties of the material elevate fun by the slow oxidizing process, form a beautiful patina on the surface.
To which some say yay, some say nah. I personally absolutely adore the result and of course the journey in between.
Mainly two types of alloy in the market that were used. CuAl10Fe5Ni5 and CuSn8.
In layman's term, simply Copper-Aluminum alloy and Copper-Tin alloy. Mostly for marine use and minor parts under pressure.
They mainly contain copper, which yields great flexibility, corrosion resistant and wear resistant from it.
Much like other material, a lot of variations deviate from Gold.
What we normally call white gold, it's a white alloy made from gold and other white metals.
Among them, the percentage of gold is up to 75%. There are 18K, 14K and other varieties.
It is a natural white precious metal. The purity of platinum is usually 95%. The annual production of platinum is only 1/20 of gold.
This long-lasting and elegant white light is it.It is called the king of precious metals and was chosen as the reason for the wedding ring.
It is an orange-yellow metal. Pure gold has a specific gravity of 19.3 and a melting point of 1063 ° C.
It has soft texture and flexible, excellent ductility and chemically stable. Therefore, it has been used to make decorations since ancient times.
It is an alloy of gold and copper. And widely used in jewelry design and processing for its very fashionable and beautiful rose red color.
The composition of pure gold, copper, silver(zinc). Because of its moderate synthetic ratio, it has the characteristics of strong ductility, high hardness, and variable color.