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Leg vice: Reproducing the screw box


wassomeoneelse

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I recently purchased several legvises, all in good repair as far as the legs go. Two of them need to have screw boxes made to fit the main screws that we believe came with them. I have searched high and low and talked with several local blacksmiths about this and none really have any ideas except to just look for old leg vices and pillage and plunder them if I need too. I really would like to have those screw boxes made by me or have made (high cost) so I am not ruining another post vice. I hope you can understand what I mean by that. Anvilmag has a four part series on the web that goes over making and restoring most items on the leg vise except for the legs. Is anyone familiar with this process? If you have ran into this problem before, how did you make the leg vise work for you? That can mean no screw or screw box. Any suggestions, parts, ideas, etc. would be appreciated. I do believe we will try this at least once. But I would like to hear from you guys and girls first before I decide on a course of action.
Thanks,
Bryan Arnold

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I have never tried this but it appears that the vice screws are Acme threads.

I have in my stock of vices a vice with an Acme nut and a small plate or large washer to give better bearing of the nut on the vice.

If they are standard Acme threads a Acme nut could be purchased and cobbled to gether to make the vice work. If you had access to a lathe you could make a box and fit the nut in the box.

I feel the older the vice is the less likely it is to be a standard Acme thread

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RFunk... my buddy and I have dicussed this same concept. I would love to make a box screw that matches what others originally came with, but at the same time, I do need to be practical about it. I think with the right acme nut welded into the hole as a guide and a another behind it might actually work. I would need to figure out how to put a knob and handle on the end. Nothing gorilla welding wont fix, but I am just itching to see if I can do it. The instructions basically say to forge metal around the screw and do another sheet 2/3 rds the length over the first sheet. put two pieces of metal to stop it from turning on the first sheet of metal where the second piece didnt cover. Then wrap the screw with a long piece of metal that you have forged to fit inbetween the screws. Screw that in the box and take out. Then pour brass in there, flux and heat.. Pretty simple sounding but much more to it than that.

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Most vices are closer to a square thread than an Acme (which was/is a patented form). Sometimes, they look like Acmes after many decades of use but they most likely started life as a square thread. If you have a lathe and the skill to do it, you can make a box insert to fit the screw - or make both pieces from scratch.

However, you can also babbitt the box with the screw in place. A full length thread which is secured into the box so it will not pull forward under load will work just fine if kept well oiled. This is a cheap and reasonably easy fix if the thread on the screw is in good shape.

I did this on a cast iron box that had completely failed. All of the interior threads had broken out over time so the screw (which was in pretty good shape) just pushed right through the box. I drilled four holes and put four machine screws into the box where they would not interfere with the vise screw but still allow the lead to form around them as anchors. I oiled and set the screw vertically in the box, dammed up the bottom with oakum, heated the box to smoking and poured in the babbitt. After cooling, it took some work to break the screw loose as the middle was more worn than the ends but patience won out in the end and the vise was eventually restored to working condition - without having to resort to any machining. A friend of mine now owns this vise and uses it regularly - the repair is about 15 years old and still holding.

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  • 7 months later...

I rebuilt a vice with striped threads. I bought some used scaffold jacks/screws, used a band saw and cut the old female threads off and trimmed down the Ears of the "nut" welded the first pass on the old end with Nickle rod then used 7014 to attach the nut to the old end or box. I cut the "all thread" male side off of the end with the slide bar chamfored the new "all thread" which was cut to the same length as the old male end, made the first pass on the cast iron piece with the slide bar with nickle then 7014. Ground the welds down to look neat and clean. Just be sure the screw of the jack will fit inside the "box" end. Around Oklahoma the Jacks run about $25.00 new or about $15.00 used. I have using my vice for about a year and have had no problems. any questions E-Mail me at Waylon63@aol.com

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One of the guys in my guild pointed out that the screw used on metal scaffolding has a box thread and nut that could be used. also the older type office chair has that type of thread. if you cand find and old operator chair from the phone company they had them also

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I have never had to rebuild a leg vise but i repaired an old vise years ago that i got a acme flange nut that seemed to fit the thread i bored out the backside of the origonal piece so the flange nut would fit then brazed it in if a acme nut would work for you mcmaster carr has many diferent typs of nuts that may work

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My vice is refitted with a acme screw and nut and a piece of pipe to cover the exposed threads it works great. welded to the old handle with 7018 rod I am tough on vices and it has held up well. No problems at all and I do wrench it down. there was also a series of articals in a magizine called anvil july 2001 it was a 3 part artical on rebilding a leg vice

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I picked up a bench screw, the threaded part of an old woodworking vise, at the local swap meet thinking I might use it to breath new life into an old leg vise missing it's screw. Wasn't sure if the iron nut would hold up to the hammering. Never thought about the scaffold jacks - Great idea! You Guys are a Fountain of Wisdom! Regards, David

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Haven't gotten around to trying it yet, but I also have several old leg vices whose threads are worn out. Bought some sections of acme thread shaft in various sizes and nuts to match. One of these days I'll see if I can replace the old shaft and nut with the new parts. If I can, great, if I can't, couldn't use it anyway. I think the shafting came from the surplus place in Lincoln, NE.

Has anybody tried this sort of reply?

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I repaired a couple old vises with worn out screws and boxes many years ago. On one of them, I used a new piece of threaded rod welded to the old screw head and handle and then welded a nut to the back of the screw box. This vise had the open back screw box.

On the other vise, I used a piece of threaded rod from an old house jack for the screw. Then I fabricated a new screw box from several pieces of heavy pipe and made new threads for the box by wrapping keystock around the threaded rod and then inserting these threads into the new box. I brazed them in a coal forge with copper wire and borax.

Both of these have been in use now for about 30 years and still working well.

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  • 10 months later...
RFunk... I think with the right acme nut welded into the hole as a guide and a another behind it might actually work.

If you weld in two nuts, they should be ON the Threaded shaft when welded in place! if they are not in proper alignment you could be creating a "Lock Nut" effect....Not what you're looking for.
Bear
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If you go the Acme thread rod route, use a coupling nut in the box. They are more than twice as long. If you have a lathe, bore out the screw box and cut down the O.D of the coupling nut .002" undersize and silver solder it in. It will never come out and look original.

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  • 8 years later...

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