Leveling Scissor Jacks

valhalla360 wrote:


Any borderline competent engineer is already including a 2-3 time factor of safety when setting the load limits.

I agree that a responsible company who produces a jack with an advertised weight rating of 5000lbs (for example) probably designs it such that it can safely handle quite a bit more load just so that there is some buffer of protection for the company's liability (and the end user).

As a consumer/user, If I am looking for a jack to lift 5000lbs I want to be extra safe so I will add in my own buffer of 2-3x (or more) just so that I know whatever jack I am using is more than capable of performing the task. I usually use a 12-ton bottle jack (24,000lbs) when jacking up one rear side (~4500lbs) of one of my 30' RVs. (And if I'm going under my RV or removing tires, I will also put some 3-ton jack stands under the frame as backup)

I would never use (or recommend) a jack to lift a load that is more than what the jack is rated to lift.

valhalla360 wrote:


The typical "stabilizing" jacks are only intended to support a few hundred pounds to take some of the bounce out of the rig. If lifting, they should be much stronger.

I haven't seen any stabilizing jacks (usually scissor type) rated for less than 1-ton (2000lbs). But I agree that even those would be only to provide some minor stabilizing to take some of the bounce out of the rig as you mention. They do have scissor jacks rated at 9000lbs+ though and I believe those could lift up to their weight rating if used safely, and thus could under the right circumstances be used for leveling an RV.

-Chris