JTB Classic Ball Screw Jack includes ball nuts that are about 90% efficient so the jacks require much less energy to lift an equal load than their machine screw jack counterpart. They are NOT self-locking so a brake motor needs to be included in the drive system and hand wheels are not a recommended option. Ball screw jacks reliably move and accurately position loads up to 35-tons. Our configures jacks with components such as motors, gear reducers, shafting, coupling, and motion control devices to create complete multi-jack systems.