The waterproofing of the watch should mean that no water droplets or water vapor can reach the movement part, and it should be solved by measures such as sealing rings. Those with high requirements, such as models requiring 200 Pa waterproof, will be installed in a positive environment when assembled. Allow the space inside the watch to always retain a pressure greater than atmospheric pressure to avoid the penetration of water vapor.
Of course, at least the casing must be answered with materials that will not rust, such as stainless steel, precious metals, alloys, plastics, etc.
1. The hardness of stainless steel is much higher than that of aluminum alloy, and it is not easy to damage;
2. The corrosion resistance of stainless steel is much higher than that of aluminum alloy;
3. The finish and decoration of stainless steel are better than aluminum alloy.
Aluminum alloy is light and not as heavy as stainless steel, but stainless steel feels more comfortable to wear and is suitable for long wear.