Spiral jacks have the core advantages of strong load-bearing capacity and mechanical braking. Their internal precision threaded structure can effectively lock the static position of the lifting sleeve and the top cover carrying heavy objects, providing convenient working conditions for operators and reliable protection for surrounding personnel and equipment. The overall performance is stable and the safety factor is at a high level.

However, with the accumulation of usage time or due to multiple overloading operations and other non-standard operations, the internal threads of the jack will gradually wear out. This loss will directly weaken the self-locking maintenance function of the thread, resulting in varying degrees of sliding of the heavy object during the lifting process.

Therefore, when it is found that the screw jack cannot maintain a stationary state and slowly falls back after lifting the heavy object to the set position, priority should be given to checking whether the thread wear has reached a critical level. If it is confirmed to be such a fault, the worn threads should be immediately scrapped and replaced with new thread components that are completely consistent with the original specifications and models.

In addition, the "Regulations on the Safe Use of Jacks" have made clear regulations: when the thread wear of the screw jack reaches 20% of the original size, the equipment must be strictly prohibited from being put into use.