I got two similar jacks from 2 different vendors last week.

obviously they are screw jacks and quite hefty see grease tube for size comparison

odd thing is they are meant for permanent mounting, I think

the screw goes thru the plate so they won't work as a regular jack

both are from the Utica NY area, but that doesnt tell me much.

any help or wild ass guesses are welcome

jul242 by Skip Albright, on Flickr


jul243 by Skip Albright, on Flickr


jul244 by Skip Albright, on Flickr

Nice, those things are massive. What is the diameter of the thread? Looks to be about 1 3/4" or so.

I thought of house-mover jacks, but then I saw this:

https://youtu.be/bcqJxMus71k

Ellis makes a whole line of shoring equipment. We used to use them building parking stuctures