The screw jack, also referred to as the mechanical jack, is driven by a manpower through a screw pair, and a screw or nut sleeve is used as a jacking member. The normal screw jack supports the pounds by the thread self-locking function, and the framework is simple, however the transmission performance is definitely low and the come back stroke is slow. The thread of the self-propelled screw jack has no self-locking action and has a brake. When the brake is certainly released, the weight can be quickly lowered by itself and the return time can be shortened, but the structure of the jack is usually complicated. The screw jack can support heavy objects for a long period, and the maximum lifting capacity has already reached 100 tons, which is trusted. Following the horizontal screw is usually mounted on the lower part, the weight can be traversed at a small distance.

Principle useful:

The mechanical jack is among the types of manual lifting tools. Its compact framework makes reasonable utilization of the rocking of the Conveyor Chains rocker to rotate the pinion. It is operated by a pair of conical gears to operate a vehicle the screw to rotate and push the lifting sleeve so that the excess weight rises or decline.


1. Before use, it’s important to check whether the jack is normal, whether the components are flexible, increase lubricating oil, and correctly estimate the fat of the large object. Use a jack of suitable tonnage and avoid overloading.

2. Adjust the technique of supporting the teeth on the rocker. First of all, turn the rocker directly in the clockwise direction by hand to make the lifting sleeve quickly ascend the very best weight.

3. Insert the handle into the rocker hole, move the deal with up and down, and the fat will rise. When the reddish colored warning line shows up on the lifting sleeve, the handle ought to be stopped immediately. If you need to lower one’s teeth in the contrary direction, the fat will start to fall.


1. Always keep the top of machine clean, verify the internal structure regularly, make the pinion in the rocker versatile and dependable, and lift the lifting sleeve openly.

2. The friction surface between your lifting sleeve and the housing must be oiled anytime. Other essential oil filling holes ought to be lubricated regularly.

3. To be able to consider the safety in use, avoid overloading, work with illness, it isn’t appropriate to use multiple units to avoid danger.