Mechanical watches are mechanical, automotive is mechanical. Cars need regular maintenance, mechanical watches, of course, also need maintenance. High-speed rail, aircraft need regular maintenance. Mechanical watch is through the clockwork, gears, escapement (balance spring, balance wheel, pallet fork, escape wheel), etc. to achieve the timing function to lubricate the gear shaft and gem bearing lubrication. As the watch is worn longer and longer, the oil will become more and more viscous, in addition there will be very tiny dust inside the case, mixed with the oil to become sludge. Oil sludge will hurt the gear shaft, damaging the life of the watch movement. Therefore, a mechanical watch worn every four to five years should be fully cleaning the movement, which is commonly known as "wash oil." Disassemble the movement, with chemical solvents to clean each part of the sludge, and then installed in the movement, debugging accurate. This process must be completed by professionals. In addition, each watch has a waterproof rubber ring. This lap is crucial, but the rubber will age so the lap should also be replaced on a regular basis. Watch maintenance also includes re-hydraulic pressure on the watch to ensure its waterproof performance. Proper maintenance of mechanical watches, life expectancy of up to 200 years, this is an important reason mechanical watches can pass away.