Problem with post vise

[Mike Turner]

Hi all I just picked up a Iron City 6" post vise cheap. The problem with it is the screw is stuck in the nut and it appears to be cross threaded or something. I think it maybe cross threaded as it has pulled a burr off the front of the nut. The vise it self is in great shape jaws are very clean. Any suggestions? I will try and get a picture up tomorrow.

[Ferrous Beuler]

Changed the oil in your car lately?
Put old contents from block in bucket.
Let simmer, head down in bucket.
Come back later and slowly work...:(Dan

[Mike Turner]

Dan it is not rusty, I think someone way over tightened this vise as the handle is bent real bad which you will see when I can get some pics up.

[Thomas Dean]

I think this is the problem. I doubt that it is cross threaded, more like a pulled thread from over tightening...hence the bent handle. I would try to soak it in warm oil like Dan OHare suggested...what have ya got to 'loose'? (intended) Good luck.

[Steve Sells]

I admit that not having seen the vise its hard to guess,

BUT have you really looked at the monster threads on a post vise? King Kong would have trouble cross threading one of those. try the warm oil.

[hdwarner]

try putting tension on the handle while tapping with a brass hammer on the front
of vise handle where cross bar is go back and forth with your tension ,
simulate an impact hammer ,
if in fact it is cross threaded evetually there will be movement and it should probally break loose

[jayco]

Mike, if it doesn't look cross threaded, I might suspect that some foreign object (a sliver of steel) perhaps has gotten stuck to the greasy screw threads and accidentaly got mashed between the threads of the nut & screw.

I've had this happen several times with ordinary bolts and nuts.

If this is the case, it would still be hard to get loose, but the threads might not be ruined after all.

Also, the handle could have been bent by some one else trying to free it up.

Good Luck!

[Ten Hammers]

Juniors trick with Marvel Mystery Oil works. Heat a bit, put some MMO in the part. Heat again till the oil sizzles a bit ( might add another pinch of oil) and come back tomorrow. I keep it in a standard gravity thumb oil can for air tool oil and other uses.

[Daryl]

I seriously doubt the threads being cross-threaded. If the threads are straight-cut or Acme threads, someone able to cross-thread such would be a miracle worker. I suspect the threads may be worn and then subject to over-tightening. You have probably three options: 1. Find another screw and box set (most don't work well mis-matched), 2. Weld up another set from Acme screw stock and nut (the most efficient good, reliable method), 3. I believe somewhere on this website there is an outline of the old method of brazing new threads in the box-end using older methods (never tried that myself).

[Dragons lair]

Mike check ebay #220190704838 screw and box

[rthibeau]

I agree with the general consensus on the soaking in warm oil gambit....that and a bigger gorilla than the one what stuck it in the first place. If it was cheap enough, I'd be happy to take it off your hands so you wouldn't need to bother. :)

[Mike Turner]

Thanks for all the replies, I now have the pics to show what is up with this vise. It appears that the screw maybe almost all the way out maybe an inch or so of thread still in the box. The thread on the screw is in good shape.

So now what do you all think?

[rthibeau]

looks like the screw is bent

[Mike Turner]

Richard I was looking at the photo with it on the ground and it was bugging me. The screw is in cockeyed in the box. The screw is straight.

[ThomasPowers]

The screw does not appear to be excessivly worn but the system has been greatly abused as you can see where the screw box has cracked and the last bit started to peel off.

Someone probably tried to over tighten it when it was almost fully open.

I would clean the screw as much as possible, oil and try to close it while apply a goodly ammount of pressure on the system to close---need a press or make up one with a C frame and a bottle jack.

It may have been sprung in which case a new screw and screwbox are in your future.

If it is just the last little bit that is bad you could trim the screw box back to "good" and use it like that.

[Mike Turner]

Hi Thomas the problem is I can not turn the screw at all. I am tempted to try and force it to unscrew it but thought I would see what others thought first. I have been soaking it with penetrating oil for a few days.

[agsolder]

I would anchor it to the post where you plan to use it, give it a good daily soak with B'laster (try your local NAPA dealer), best penetrant I've come across, for a week or maybe two, and if that doesn't free it up, using a pipe wrench and a cheater, but gently, I next try gentle heat on the box. Patience is the key when reincarnating old rusted, jammed tools. I once bent the handle on a big old (U.S.-made) Ridgid pipe wrench loosening a vise in this shape, but it did eventually come free.

[J W Bennett]

Mike,
At this point I beleive I would wrap a water soaked rag around the screw and heat the Female section As quickly as possible. Have a pipe wrench handy and with someone still heating the female section I would try to unscrew it. The damage is done...I don't think you'll hurt it much more.

Good Luck

John

[ThomasPowers]

1 further method, check to see how much screw engagement is there and if very little saw the screwbox just abaft the end of the screw and then remove the part stuck on the screw---grinder/saw/whatever.

This is of course a "Nothing else worked approach".

[Paragon]

I would lean towards what Thomas said.. but if there is a lot of screw left, I would cut the "box" at the crack around the whole thing and not cut through to the screw. Get rid of that part. Then go from there.

Sounds like the vice got fubar'd and was left to rust in a corner. I don't see how anything else could be holding it... without looking at it myself.

[Mike Turner]

OK I stuck a rod in the hole on the box and marked it for length and it looks like there is about 3" of thread stuck in the box. I clamped it down and put a 4' pipe over the handle to see if I could move it not a chance all I did was straighten out some of the bend . I have it soaking in penetrating oil and will give it a try again tomorrow, if that don't work I will get a friend to help with the heating process.

[tecnovist]

Mike Turner
Hi --- I had one like that had a damaged thread after getting it out useing a gas touch it heat it--- i cut a groove like a gap along the lenght of the nut -- I also deepened the thread on the bolt with a disc grinder--- then closed up the gap in the nut and welded up the groove = OK a don't lean on the handal to much ----

--- When you heat it use never-seze --- you could even fit a grease nippel on to the nut then pump never seaze in then heat the nut ----

right I see the crack in the nut I would use a disc grinder with a cutting disc and cut the crack open -------undo the nut&bolt---file things up to a good fit---- vee out the now cut crack PUT NEVER SEZE on the nut&bolt clamp it onto the bolt then weld the vee up on the nut ---{{{ do not breath in the smoke }}} Let things cool before you turn them----

Remember a good weld can only be done with a good fit up

[philip in china]

What penetrating oil are you using? Not a good idea to leave things soaking in some brands. I am not sure about US brands but somebody here will be. Did you try the warm, used engine oil? It absolutely cannot harm.