According to its material, the case is divided into gold case, steel case, aluminum case, copper case, titanium case, alloy case, plastic case, wooden case, etc. Usually, the watch that we touch, use and choose the most is the watch with all-steel case and strap. But you may not know that there are many watches advertised as all-steel cases that are actually copper cases.

a. The coating of the all-steel case is bright and dark, and the edges and corners of the case are rounded without sharpness. The coating of the copper case is bright and whitish, the back of the lugs is sharp and the back of the lugs is generally clear to see the ring pattern formed by the cutter. And the texture is different in depth and size, and the arrangement is loose and uneven. The texture of the all-steel case is fine and well-proportioned, and the arrangement is tight and neat.
b. Gently scrape the corners of the lugs (which can be inspected on the inside of the back of the lugs) with a knife within a short distance, if the inside is yellow, it is a copper case. c. The copper case has poor corrosion resistance. If it is improperly maintained and used for a period of time, it is prone to fading (yellowing or redness), blistering or peeling of the coating.