One day, years ago, a buddy and I didn’t have anything to do. So, we raided the dumpster at Jorgensen steel (sadly, under lock and key, these days) and pulled that piece of hydraulic tubing, along with a few others. It is 4140, seamless, drawn over mandrill, 1/4” wall tube, that was polished internally and externally, for a two stage hydraulic ram of some sort. We welded flanges on it, filled it with spent lead shot and motor oil, and bolted it to the floor, and drilled and tapped the upper flange to fit the vise. It does not swivel, but, you can walk completely around it, so, no big deal.
The lead shot and motor oil make it dead blow.
If you don’t have a well mounted, and good quality vise in your shop, you don’t really have a shop.
I have three vises. A few vices, as well, but, that is for another time.
Jon I can’t remember what size they were, either. Once the wheels are true, I forget all about them.
Ted