Spiral jacks are different from hydraulic jacks. When lifting heavy objects, they rely on a spiral transmission system. Since there is no hydraulic transmission system or hydraulic oil inside, even when used upside down, there is no need to worry about oil leakage. However, will there be unstable lifting when used upside down?

Because when in use, the thickened base of the jack is in direct contact with the ground, and the top cover is in contact with the heavy object. The area of the base is larger, and the contact area with the ground is also larger. When carrying heavy objects, the stability is relatively good, and unless there is a biased load on the heavy object, the jack generally does not tilt or collapse.

If used in reverse, the situation would be very different. A very small top cover is located below and in contact with the ground, while a larger base is in contact with a heavy object. When hand cranking the joystick, there will be no inconvenience. To prevent heavy objects or jacks from collapsing, the left hand needs to tightly grip the handle, so more force is required.

So the screw jack can be used upside down, but when using it upside down, be sure to hold the jack firmly to prevent it from tilting.