
Originally Posted by
Paul C
Are you certain it is the plates and not the hinge pin? I have a vise that always shifted as I was tightening it down. After years of dealing with it and finding no other source for the problem, I extracted the pin and noticed a groove worn into it, almost halfway through. Fixing the pin fixed my problem.
Ooh Paul, I have that exact issue with my vise, I'll check that out. I also need to re-weld the nut that had been welded to the front of my vise. Here is a pic.

I figure the vise was rebuilt at one point with a new screw and they welded a big square nut right behind the tightening knuckle and mounted the rest of the screw hardware on the back. It's quite a bit longer than most compete vises I've seen. It still works nicely though, except for the pivot on the jaw when tightening. I think I'll likely have to cut the bolt to get it out, but I can replace it too. 
Regards,
Tim
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Mark Twain