how to fix a threaded ferrule?
- Thread starter JoBo
- Start date
How loose?
It's a rivnut, also known as a nutsert. It needs a tool a bit like pop rivet pliers (but not actually pop rivet pliers) to fasten it into the sheet metal. And if it is not in sheet metal, it is the wrong thing for the job.
Roger
Roger
Not all sert nuts are the same design. Some are smooth others serrated.
Roger is correct.
If turning now & it has been pulled previously, to get out if possible angle to load the bolt until it tightens the seat nut enough in the hole to screw the bolt out.
When out enough jam a screw driver under the sert nut lip to lever & lock so the crew comes out fully.
Try to get seat nut out without enlarging the hole further. They can be crushed easily to facilitate if access on both sides.
Often incorrectly fitted.
No special tools needed just a long bolt, round sleeve bolt fits through, then sert nut through correct size hole. Hold sleeve with vice grips & tighten the long bolt with a wrench until sert nut is crushed to tightly hold in place.
If hole is too enlarged from spinning go to next size up thread size & re drill hole to this size.
Roger is correct.
If turning now & it has been pulled previously, to get out if possible angle to load the bolt until it tightens the seat nut enough in the hole to screw the bolt out.
When out enough jam a screw driver under the sert nut lip to lever & lock so the crew comes out fully.
Try to get seat nut out without enlarging the hole further. They can be crushed easily to facilitate if access on both sides.
Often incorrectly fitted.
No special tools needed just a long bolt, round sleeve bolt fits through, then sert nut through correct size hole. Hold sleeve with vice grips & tighten the long bolt with a wrench until sert nut is crushed to tightly hold in place.
If hole is too enlarged from spinning go to next size up thread size & re drill hole to this size.
I have fitted dozens of these in place of caged nuts & do have a special puller.
The sert nut maker usually specifies the drill size. I usually go a little under.
Properly pulling to crush is important & personally I don't like the Kingchrome smooth ones from Bunnings.
Get good ones from a bolt shop.
Not cross threading is imperative & I always coat the bolt thread with Kopr Kote? type grease.
The sert nut maker usually specifies the drill size. I usually go a little under.
Properly pulling to crush is important & personally I don't like the Kingchrome smooth ones from Bunnings.
Get good ones from a bolt shop.
Not cross threading is imperative & I always coat the bolt thread with Kopr Kote? type grease.
If you have not got the nutsert in the hole i.e. just the hole; you can try peining around the hole with a ball pein hammer to shrink the size of the hole. If you do it carefully you will most likely not notice the deformation of the metal when the nutsert is in place and crushed.
It is loose enough in the hole to spin by hand . One fix here is to fit a nut, then flat washer, to a longish bolt, run them part way down, then screw the bolt into the rivnut. Hold the bolt head to prevent it turning and tighten the nut so it pulls the bolt in order to collapse / mushroom the bottom of the rivnut until it no longer turns. If the thread is metric 1.0 pitch, one turn of the nut pulls the bolt and crushes the rivnut 1mm. Then remove and fit the correct bolt. That is all that the correct tool does and the rivnut has those axial grooves to promote the mushrooming effect and to grip the surface to which it is being fitted. It simply looks like it wasn't properly installed at the factory. Look for some pics and vids of how to install a rivnut and you will get the idea.
It only aluminium by the looks of it? My rivnut gun can provide enough pressure to deform the threads on the alloy inserts to the point where it's nearly impossible to get the tool to unscrew.
If you are going to use the nut/bolt spanners idea just nip it up, don't wrench on it, and when you fit the proper bolt just nip it up too.
Fun fact, my auto correct turns rivnut gun into rabbit gun.
If you are going to use the nut/bolt spanners idea just nip it up, don't wrench on it, and when you fit the proper bolt just nip it up too.
Fun fact, my auto correct turns rivnut gun into rabbit gun.
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Same as the sleeve held with vice grips.
Just a suitable nut de-treaded so as to fit snuggly over the bolt shank & can be then held with a wrench instead of the vice grips.
Screwing the bolt in while holding a sleeve is akin to tightening a bolt into an alloy casting.
Holding the bolt and screwing a nut down the bolt is akin to putting a nut on a stud to tighten something down to an alloy casting?
If you are unsure of how much pressure to apply (as with any threaded hole) the second option is safer for the threads, (maybe put a flat washer with a little lube on both sides between the nut and the nutsert to stop it "grabbing" the nutsert as well)? If you use a long enough bolt you can keep pressure on it with a socket while you tighten the nut.
Hence the rivnut gun's operation pulls on the threads, it doesn't twist.
Just my 2c worth.
Holding the bolt and screwing a nut down the bolt is akin to putting a nut on a stud to tighten something down to an alloy casting?
If you are unsure of how much pressure to apply (as with any threaded hole) the second option is safer for the threads, (maybe put a flat washer with a little lube on both sides between the nut and the nutsert to stop it "grabbing" the nutsert as well)? If you use a long enough bolt you can keep pressure on it with a socket while you tighten the nut.
Hence the rivnut gun's operation pulls on the threads, it doesn't twist.
Just my 2c worth.
I was going to make a silly joke here, using the word "Babbitt", which I had heard but didn't know the meaning of. Upon Googling, I now understand a bit more. Having seen plenty of bearings, I had known the concept but not the applicable word..It only aluminium by the looks of it? My rivnut gun can provide enough pressure to deform the threads on the alloy inserts to the point where it's nearly impossible to get the tool to unscrew.
If you are going to use the nut/bolt spanners idea just nip it up, don't wrench on it, and when you fit the proper bolt just nip it up too.
Fun fact, my auto correct turns rivnut gun into rabbit gun.
Babbitt (alloy) - Wikipedia
My father learnt his trade in the '50s and he often spoke of pouring and scraping babbitt bearings, particularly on old truck engines. I would still have his bearing scrapers here somewhere, not that I know how to use them.I was going to make a silly joke here, using the word "Babbitt", which I had heard but didn't know the meaning of. Upon Googling, I now understand a bit more. Having seen plenty of bearings, I had known the concept but not the applicable word..
Babbitt (alloy) - Wikipedia
en.wikipedia.org