I have only rarely found a use for a tractor jack other than on a piece of farm equipment.
I do remember one time in a wheat field when we had a 3/4 ton stuck in some real deep stuff. We had a tractor jack a BFH and a winch! Get the picture? that jack made some deep furrows before it got us out of there. It was useless after that and got replaced with a new one.
BJ