What are silver-coated, gold and electroplated watch straps?
In terms of the purity of silver, 925 is not the highest purity of silver. You can see that the domestic real-time silver price has 99.99%, 99.95%, 99.90%, and three transaction purity. These three are too soft to make jewelry. Generally 92.5% is the most suitable for jewelry (hardness, ductility, etc.). So 925 can also be called sterling silver. But it’s not really pure silver. Silver is an ancient precious metal, the most used material for pocket watches in the eighteenth century and before. 925 represents the purity of silver, the highest purity of silver. The common ones are 925–suitable for jewelry, 975–suitable for tableware, 990, and more pure ones. Silver is an active metal that easily reacts with sulfur in the air. A black oxide layer appears, making the silverware black. Nowadays, it is far inferior to gold in watch applications. The reason is that it easily loses its luster due to water, moisture and other reasons.
The gold-clad case is made of stainless steel, wrapped with a layer of gold alloy, and mechanically rolled into a whole. Its thickness is measured in microns, and 1 micron is equal to 1/1000 millimeters. The maximum thickness is 10 to 15 microns, and generally only 2 to 3 microns.
Electroplating is a common method of decorating the case of modern watches. Electroplating technology emerged in the 1970s. Because the electroplating is uniform and firm, the cost is lower than that of gold coating and it is not easy to fall off. There is no possibility of discoloration and corrosion of the forged yellow shell. So they will soon be eliminated from the market.