Standard JACTON screw jacks lifting screw with right hand threads. Face to the nameplate of jacks, for upright type jacks, when we rotate the worm(input shafts) clockwise, the lifting screw will be go down(retract motion). If we rotate the worm(input shafts) anti-clockwise, the lifting screw will be go up(extend motion). For inverted type jacks, when we rotate the worm(input shafts) clockwise, the lifting screw will be go down(extend motion). If we rotate the worm(input shafts) anti-clockwise, the lifting screw will be go up(retract motion).

When multiple units screw jacks make up to a whole screw jack lifting systems, all screw jacks lifting screw rotation direction must be say, then will be synchronized lifting as a system.