Ah, well, that's probably a good point. Mine is an old 7" non-quick-release type. I just re-did it a bit ago, and I removed the little plate on the back that keeps the screw from coming out. Pulled the screw out, wire brushed the grunk out of the pits on the threads, waxed it, then cycled the screw all the way a couple of times. It's realllly smooth now. Much better than it's been since I restored it.
That vise was an interesting find. It fell off the back of a waterbed store's delivery truck. Guy said it was on there when he bought the truck. He looked at it, looked at me, said "Here, you want a vise?"
I could tell it was some kind of face vise, and it looked old, but it was a complete rust bucket. It was and adventure spanning years getting that thing to work again, and it was well worth the effort. Even though there's some pretty serious pitting on all the threads that weren't inside the gigantic nut, it still works perfectly. That much more perfectly now. I finally even got the pop-up dog to where my son can pop it up. It used to be mighty stiff.
There's nothing like rescuing a gigantic hunk of cast iron from oblivion. This thing could have been made anywhere between the '20s and the '50s. I can't date it closer than that. One things for sure though: they don't make'em like *this* anymore. Those new ones for $100 look incredibly wussy next to this monster. I just wish it was a 10" quick-release version from the same company. Oh well, you can't get everything for free.
Sorry. I ramble about this thing from time to time. I sure am proud of it.