For My Bridgeport Mill, I made machine feet. They are made from 1"-10 threaded studs and same thread nuts, welded onto 1/4x1.5x4.75" steel flats.

The hex area on the top of the studs, is 3/4", the same as the rest of the bolts on the mill.

I welded those feet that I made, onto the mill's movable base. The first stud became hard to turn. After some thinking, I realized that the decision to weld along the whole length of the bar, was wrong. I welded the rest, with four 1" long welds, along where the nuts are attached (most rigid areas). Remaining ones were not stuck at all. Then I used a 12" Starrett precision level to level it. The level turned out to be very sensitive. After about 45 minutes, if not more, I finally got the mill leveled. It was a "step forward, two steps back" kind of procedure. But finally it worked. At the end of leveling, I realized that the mill was only standing on three legs, with the fourth not touching the ground. Very embarrassing. I then slid a piece of paper inderneath that leg, and gently lowered that leg to the point where the paper just became firmly stuck underneath it. I verified that the mill remained true.

(Click on the thumbnail images to enlarge)