The hydraulic jack will be fatigued after a long time of use. In this case, there will be a great potential safety hazard if the jack is still used. At the same time, the service life of the hydraulic jack will be shortened. The fundamental cause of all this is mainly mechanical fatigue.

Mechanical fatigue refers to the phenomenon that materials, parts and components produce local permanent damage at a certain point or some points under cyclic loading, and form cracks after a certain number of cycles, or make cracks further expand until complete fracture. If the hydraulic jack is used for a long time, the continuous and repeated lifting of heavy objects is prone to mechanical fatigue, resulting in the phenomenon of equipment friction and overheating. After the temperature rises, the hydraulic oil will deteriorate, and the lubrication and lifting capacity will be much worse than before. If the hydraulic jack continues to be used, 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.

For long-time continuous operation, not only people will be fatigued, but also hydraulic jacks will be fatigued. The use of mechanical fatigue will not only reduce the construction efficiency, but also affect the construction safety.