REQ: how to remove threaded rod

Problem:
3/8 in. threaded rod through nut welded to outside of rectangular
tube frame.
Tube is ~2 in. x 3 in. with ~1/4 in. wall thickness.
Ends, inside, and top of frame are not accessible.
Nut is welded to short side.
Threaded rod used to have "foot" attached .
Rod has ~3 in. inside frame and 1 in. extending outside.
Rod used to turn.
Rod will not turn with vise-grips.
All material is steel.
Threads appear damaged. No corrosion.
ASCII ART (please use fixed-width font):
__________________________
_--| ^
_
-- ~ | |
|~ | 3 in.
| frame | |
| tube | |
| |_____V_____________________
| _-- __ ^
| _ -- ~ nut ---> / \ | 2 in.
| ~ \__/
|
_______________________| | _____V______
rod ---> | |
|__|
Q1: How would you suggest to remove rod?
Q2: If it is decided to weld a big honkin' nut to the end of the rod
to facilitate application of absurdly high torque values, what method
of welding would you suggest?
Q3: What method of welding would minimize total heat into rod?
Then kew kindly for your assistance.
Reply to
Dev Null
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Heat is actually your friend on this one. I'd probably soak the rod and nut with Kroil, PB Blaster, or Automatic tranny fluid for several days or at least several hours. Cut off the threaded rod to leave about an inch or so protruding. Set a 1/2" NC nut down to within a couple threads of the workpiece, weld it solidly on with MIG or stick. While it is still hot, try turning it out.
Dev Null wrote:
Reply to
RoyJ
Before you totally cream the nut by trying to remove the seized rod.... cut the rod off flush. Drill it out through the nut to the minor dia. of the rod threads. Run appropriate tap through the nut to finish. This procedure requires a surgeon's touch, sharp, straight tooling, and, of course, dead center and axial drill path. It CAN be done. Good luck.... JR Dweller in the cellar
Dev Null wrote:
Reply to
JR North
Which part of the assembly are you trying to save? Likely, something won't survive if the rod won't turn.
Throw a grinder at it and move on.
Regards,
Robin
Reply to
Robin S.
I've only tried this once and it worked perfectly, I knew enough to quit wile I was winning. Gerry :-)} London, Canada
Reply to
Gerald Miller
Weld a nut to the end of the rod.
MIG or Stick welding would both work fine.
You WANT heat. The best procedure I have used is a progressive one. Start with a torch, propane at least, but preferably Oxy/Acet. Warm the rod then shoot penetrating oil into the joint between the nut and the rod. A little more heat, then more oil. Do this a few times before even trying to move the nut. Don't try to turn the nut out in one go. Start by working it back and forth to break it free, while adding more oil to the joint. Eventually it should work free enough to get it out. I have used this technique on dozens of stuck bolts and engine studs.
Don't be stingy with the heat or the oil, but don't heat it above a dark red. Too hot and you will oxidize the threads too much.
Reply to
Ernie Leimkuhler
JR is right you can drill to the root of the thread then pick it out. I had a broken bolt and broken tap extraction business for 18 years and I made tools just for that job. For that size I would take old 1/4 drill bit and cut it off just at the base of the flutes, then grind about a 45 degree angle on drill, that part of the drill will still be hardend. And the bottom part of drill will not be heat treated. Now take the sharp pointed part of drill and pick the core of the threaded shaft away from the wall . Often you can grab the remaining thread with a needle nose pliers and pull it straight out. If it breaks apart in pieces then go back with the pointed drill pick and use a wire with a hook bent on the end to pull out the pieces. Wear eye glasses. The reason to use an old drill is hitting the soft end is less likely to shatter. And the 45 degree angle pushes the core out to the center so you can grab it. Keep tool sharp. Jim
Reply to
Jim Sehr
First, nice job with that ASCII Art! I have had to do that before, and it takes a while.
My solution: Do you have a cutting torch or a grinder? If so, cut or grind the old nut off of there. That will get rid of the rusty nut and the damaged threaded rod. Then, go to Tractor Supply Co and get a new nut/rod to weld in its place.
Good luck, ~Joe
Reply to
jp2express
"Gerald Miller" wrote: (clip) requires a surgeon's touch, sharp, straight tooling, and, of course, dead center and axial drill path.(clip) ^^^^^^^^^^^^^^ I have done this, and I DO NOT have a surgeon's touch. Don't let that scare you. Start with a small drill, and center it the best you can. Use increasingly larger drills until you are just about to start cutting the threads on the inside of the hole. This will give you a thin shell that you can collapse, pull out, pick out or remove with a tap. At that stage the metal is so thin it can't fight you, and you will get it out (in shreds.)
Reply to
Leo Lichtman
If you can get visegrips on the rod on the inside of the frame tube, you might do as JRN says except drill to slightly less than the minor diameter and then try to turn the rod from the inside of the frame tube.
Dan
Reply to
dcaster
"jp2express" wrote in news:Jvsii.23920$ snipped-for-privacy@newssvr23.news.prodigy.net:
Thanks to everyone for your replies.
Every time I tried to weld (SMAW, 3/32 E6011) a nut onto the rod, the rod sheared off at the weld. Probably just bad welding, but my excuse is it was overhead.
If I didn't have to weld overhead I would definitely have cut off the old nut and welded on a new one.
Reply to
Dev Null
I missed the beginning of this thread but it sounds to me like an ideal application for a nut splitter (or a cold chisel, hammer, and something heavy for backup).
Don Young
Reply to
Don Young
Heat it red hot and while it is hot apply parafin wax to it. Hot parafin is a great penetrating oil. I learned this trick when I was a kid hanging around a heavy eqpment repair shop. The guy would treat inch thick nuts like this and you could tell where the parafin penetrated all he way through the rusted on nut
Reply to
Jimmie D

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