The main advantages of screw jacks are simple manufacturing, cheap price, less maintenance, ability to maintain the same clamping force, no oil leakage, and no dirt on the site. The disadvantages are low transmission efficiency and slow return travel. Therefore, in the case of insignificant productivity, their advantages are still in the leading position. Therefore, in recent years, ordinary structure screw jacks have still developed rapidly, and their tonnage and weight are also constantly increasing.