The ActionJac self-contained screw jacks from Nook Industries, Cleveland, Ohio, are totally mechanical, so there are no hydraulic hoses to crimp and maintain and no hazardous fluids that can leak. Even repairs are said to be less costly.
Tapered roller bearings support the worm shaft, while tapered-roller or ball-thrust bearings support the drive sleeve. And the worm gears are precision ground. The jacks come in a variety of sizes with maximum load capacities ranging from ¼ to 100 tons. While the housing can be ductile iron or stainless, users can choose screws made of stainless or alloyed steel, as well as plated and coated versions. The jacks come in a variety of configurations, including upright, inverted, rotating and translating, double clevis, keyed, and antibacklash.