stripped threads

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  #1  
Old 07-22-05, 10:26 PM
William521
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cutting threads

I have a female thread that was over torqued and unfortunately got stripped out. What happened next is we tapped it and we used a helicoil to restore it to its normal function. The thing just stripped again and this means we will have to tap it even large. Is there helicoils that are available in difference sizes that can accomodate this extra change. The female thread is metric and the male thread is just one long male bolt without a head on it. The male bolt cannot be smaller or larger in diameter so I can't just install a larger one. Perhaps if they make a long male metric bolt (without a head) that is half one size and the other half another might work. Hopefully if I tap it larger it still has enough metal in it to hold the bolts torque but for know I would like to find this out. Thanks alot. MIKE
 
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Old 07-22-05, 10:32 PM
William521
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stripped threads

I have a female thread that was over torqued and unfortunately got stripped out. What happened next is we tapped it and we used a helicoil to restore it to its normal function. The thing just stripped again and this means we will have to tap it even large. Is there helicoils that are available in difference sizes that can accomodate this extra change. The female thread is metric and the male thread is just one long male bolt without a head on it. The male bolt cannot be smaller or larger in diameter so I can't just install a larger one. Perhaps if they make a long male metric bolt (without a head) that is half one size and the other half another might work. Hopefully if I tap it larger it still has enough metal in it to hold the bolts torque but for know I would like to find this out. Thanks alot. MIKE
 
  #3  
Old 07-22-05, 11:10 PM
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The problem with helicoils, if you don't tap the hole straight they tend to pull out.

search the net for threaded inserts.
http://www.carrlane.com/Catalog/index.cfm
 
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Old 07-22-05, 11:19 PM
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Threads merged
 

Last edited by GWIZ; 07-23-05 at 03:23 PM. Reason: Threads merged
  #5  
Old 07-23-05, 04:12 AM
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Threads merged

William521,

I have not seen a stepped bolt that is available off the shelf.
A machine shop could make this for you.
If it happens to be an engine block though, you must be carefull that you have the metal thickness in the casting to enlarge the hole to this new size.
 
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Old 07-23-05, 02:49 PM
William521
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Carr lane is a good online site for products. Unfortunately they have a $25 minimum order. Do you know of any site online that sells threading inserts like this but doesn't have this restriction on it. I found what I need there and it has a 8mm inside diameter with a 12 mm outside diameter. Thanks alot as always.
 
  #7  
Old 07-23-05, 03:22 PM
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If you have a local machine shop tooling supplier they generally don't charge that minimum.

http://www.mcmaster.com/
 
  #8  
Old 07-26-05, 09:14 AM
William521
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That is one excellent site. Very complete and easy to use search engine to find many things. Thanks alot for saving me alot of time.

I started searching for alternatives and someone actually suggested that you could repair stripped threads with an adhesive. I went on the devcon epoxy adhesive website and did some looking there. They recommend using and say that Plastic Steel Putty, #10110 or Titanium Putty, #10760 would be
good choices. I'll include a link to the plastic steel putty and the titanium putty technical data sheet if you wan't to see what it is. For the plastic steel putty sheet visit this site http://www.devcon.com/techinfo/101.pdf For the titanium putty technical data sheet visit this site http://www.devcon.com/techinfo/10760.PDF.

With all that said I am really very skeptical about that stuff. It would be excellent though if I could just fill the hole with an adhesive and that would be it. I posted it here to get a professional opinion on it. Thanks as always. Will
 
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Old 07-26-05, 12:56 PM
Eddiebx
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if its somethign that is load bearing, I would suggest not going with an adhesive as it would probably just rip out.

www.timesert.com is where you can find a really hardcore insert, they cost a pretty penny but it might be what you need.

otherwise depending on the metal you might beable to just weld it up and retap it. or hell just weld a nut in there if you have the room!
 
  #10  
Old 07-26-05, 01:52 PM
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" I posted it here to get a professional opinion on it."
------------------------
My non professional opinion.
I did not try the items your talking about.

You did not state what you are holding.
The holding power of your 8 mm stud is more then likely going to exceed the strength of glue by 10 times.

It may work with small screws.
I would never use any glue for bolts. but I would use it on non critical items.
 
  #11  
Old 07-26-05, 03:09 PM
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I'll ditto the suggestion of staying away from using "glue".
Like was said, you didn't state what the bolt does.
There are issues of strength involved when repairing threads.

We are making assumptions that this might be for something that is not safety critical.
You'd better tell us what this bolt holds.
 
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