Hi, a couple months ago I got a 6.25" jaw post vise, and it was missing some parts: the spring, mounting plate, wedges, and nut for the pivot screw. I made all the replacement parts except for the nut, which I just didn't think was too important since the bolt stayed in fine without it. However, after stumbling across a thread on here about vises, I learned from one of jlpservices' posts that the pivot nut and bolt assembly is an important part of holding the tapered vise cheeks together.

Having learned this, I would like to find some way to replace the nut. The threads on the original bolt are rather messed up near the end, so I'm not sure if there's enough good threads left to work with:

What should I do? Is the original bolt salvageable, or do I need to make a replacement? The other bolt in the second photo is just a bolt of the same diameter.

Thanks!

Don't be overthinking things. It's just a pivot. As long as the jaws are lined up properly with the existing pin in place and the holes are not wallered out ( yeah, it is a word!) you're good to go. You could just slide a washer over the bolt end and drill a hole for a cotter pin to hold it all in. My vise is older, with no threads on the pivot pin. There is just a hole and a tapered  pin hammered in to hold it. I've done repairs with another bolt  from my bolt pile. You just don't want it too loose that jaw alignment is affected. EZPZ

Steve

Looks like the original has enough threads left to hold a nut (doesn't have to be gorilla tight), if not run a die on the new one and cut it off to the right length with a new nut. Or get fancy and watch the video JLP made on forging bolts.

I guess I'll keep it simple then, thanks! I'll see if I can find a nut that fits.

I you want it to pull in the cheeks on a 6.25" You will need a lot of force! Perhaps a better way would be to pull them in hot with a screwpress and one the alignment is set just use a bolt with little force.  The old vices didn't use threaded bolts but rather wedges through a slot in the shaft.

I have 4 6"+ postvises right now and none were so sloppy as to need a pivot adjustment.  I do have one that has less play in it and just use that one for tasks when I need zero play.

Does the original bolt have a little nub on the underside of the head to fit in am inlet on the outside of the cheek?

The alignment of the cheeks is fine. As I understood it, the bolt helps to keep it that way by taking some of the load off the forge welds. However, if I'm mistaken, I'll just leave it as-is and not worry about it.

Yes, the original bolt does have the indexing nub.

I was noticing the nub hole on my new to me vise yesterday---which told me that the pivot bolt was a replacement; sq headed; but still not the original!

On 1/27/2020 at 5:17 AM, Chelonian said:

What should I do? Is the original bolt salvageable, or do I need to make a replacement? The other bolt in the second photo is just a bolt of the same diameter.

An easy job if you want to preserve the original bolt.

Build up the bolt end with your welder. Take to someone that has a lathe and can turn a thread. Job done.