... shafts,couplins,guides,gear reducer etc. Screw Jack Lifting System configurations screw jacks, bevel gearboxes, flex linking shafts, ... synchronized, self locking 2. Multiple jack system, from pair jacks system to fourteen jacks system 3. Electric driven, manual operated are ... screw jack lift system is of high mechanical, they are an excellent choice when hydraulic, pneumatic or chain systems ...