I have an old HF multi-purpose bench vise that I've had for 5 or 6 years and I have abused it severely by heavy pounding on the anvil and by using a cheater bar for tightening. Well, I finally stripped the cast iron threads in the main nut as a result. I checked with HF and of course they no longer carry replacement parts for the vise. Also the lead screw is not standard acme threads so I couldn't just use an acme nut as replacement.
I would like to replace it with a good used American made vise if I can find one at a decent price. Picture of current HF vise.
I came up with the following system that I think will make the vise useable until I can find a replacement and maybe some of you guys can benefit from it as well. Total cost was about $13.
It seems to work well and the only drawback is you have to manually pull the jaws apart when it's released.
I used 3/4" threaded rod with a coupling nut on each end. The nut on the right side of the rod in the picture has a small tab welded to it that fits in the grove of the rotating shaft of the movable jaw to prevent the nut from turning while tightening (this coupling nut also fits behind the existing main nut of the vise). FYI, Surplus Center has 3/4 acme threaded rod and nuts but I didn't find coupling nuts. Their 36" rod plus one nut and shipping cost about $25.
The coupling nut on the left side of the rod has a half inch hole drilled through one end for a tightening handle. After the hole is drilled, the nut is threaded on to the rod and welded to the rod. There was some play between the threaded rod and the vise so I made an aluminum bushing to take out some of the slack. I tried taking close-up pictures of the coupling nuts on each end but couldn't get the camera focused well enough to get decent pictures..