Repairing threaded rod

[clifto]

I have a heavy-duty massager whose main structure is held together by two pieces of threaded rod about 3" long. The rods are partially stripped at the ends; nuts need to be turned to put them on, but they're quite loose. It doesn't look like it would be possible for me to replace the rods, so I'm wondering if there's any sane and relatively permanent way to repair the threads. Whatever I use has to tolerate a LOT of vibration, of course.

[Nate Nagel]

If it's a size that's commonly used for pipe hangers, there are couplers available where you can cut off the damaged section and splice in a nwe one. However, if they're only 3" long I suspect that replacement would be your best option. can you post a pic?

nate

[David L. Martel]

Clifto,

They sell nuts with nylon inserts that are very vibration resistant. They are called Stop Nuts. Most hardware stores sell them

Dave M.

[Bob M.]

I've fixed munged threads with a file, if you have a file that can fit in the thread, you should be able to use the file to make it look like a thread again. Then, maybe you can try spinning a thread-cutting die on it.

[Joe]

Use red Loctite, available at many hardware and auto parts stores. That is the most stubborn grade of thread locker in the Loctitie line.

Joe

[Al]

A new nut may solve the problem. If a new nut also slides then re thread the rod with the next smaller die and get a nut to fit that new size.

[clifto]

I have too little metal, not too much. One rod has a 3/16" section on the end such that the nut slides on.

[mkirsch1]

You've stripped the threads off. There is no practical way to fix that except by replacing the threaded rods.

If you galled the threads so the nut wouldn't thread on, that'd be different. That could be cleaned out with a thread file.

[dpb]

...

Or rethreading for smaller size or if it doesn't need to hold much force peening to create high spots and rethread. Possibly some shim stock around the thin spot might work. Lots of ways to cobble stuff up; best would undoubtedly be to replace...

Or, is there a section not used so could shorten existing, use connecting nut to extend back to original length?

[aemeijers]

If he is sure it will never need to be taken apart again, a couple spot welds should work.....

-- aem sends...