The use of hydraulic jack must have a certain degree. Even if there is no overload operation, continuous and frequent use will cause greater damage to it, which is caused by mechanical fatigue.

Mechanical fatigue refers to the phenomenon that materials, parts and components produce local permanent damage at some point or some points under cyclic loading, and crack is formed after a certain number of cycles, or the crack is further extended until complete fracture.

If the hydraulic jack is used for a long time, the continuous and repeated lifting of heavy objects will easily lead to mechanical fatigue, which will cause overheating of the equipment due to friction. The hydraulic oil will also deteriorate after the temperature rises, and the lubrication and lifting capacity will be much lower than before. If the hydraulic jack is used continuously, the accessories will be worn, and the gears, piston rods and sealing rings will be damaged. In serious cases, the equipment will be scrapped and cannot be used.

Long time continuous operation will not only lead to fatigue of people, but also mechanical fatigue of hydraulic jacks. The use of mechanical fatigue will not only reduce the construction efficiency, but also affect the construction safety.