What are the structures of waterproof watches?
1. Bite waterproof structure. The difference between it and the thread bite type is that the bottom of the watch has a thread, and the main frame and bottom case have concave and convex notches to bite each other.
2. Screw the waterproof structure tightly. This is the most common and main type of waterproof watch. It is characterized by threaded connection between the back cover and the watch case, and a sealing gasket is pressed. The edge of the back cover has 8, 10, 14 equal symmetrical corners, which can be opened with a watch opener. Although some have no thread at the bottom, the other is closed with a threaded back ring, which should also belong to this category.
3. Pressure relief and waterproof structure. The bottom case is a concave steel bowl, the watch machine is installed in the steel bowl, the tight ring and the watch cover are pressed on, the main case frame is fastened to the watch case, and the waterproof performance is still good. Its characteristic is that the case has no threads, the back cover is rounded, and the edge of the cover has a sealing gasket, which fits tightly by pressing and can be opened by a blade. But the string stem is a double-section rod, and the joint is easy to store water and rust.
4. The waterproof structure of the back cover after the knife is removed. This kind of waterproof watch is often ignored by people and mistaken for a general watch. Although it uses a knife to tuck the back cover like an ordinary watch, it is much tighter. The handle and back cover are also padded with rubber bands, which can also play a waterproof role.