Stripped stud

CanadianDavid

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Mar 3, 2021
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Not sure if theses are beginner questionsbattTerm.jpg but here goes.

I bought 16 230 ah eve cells from Basen. They are excellent quality. well matched and all perform well above rating (I am seeing between 239 and 242 ah when testing them). The only issue I have is a single stripped stud. They have what appear to be welded in studs.

Not sure how it happened, I have been torqueing these the same since the beginning. I use a torque wrench and set them at 15 in/lbs for general testing and charging and at 20 in/lbs for final assembly.

2 questions;
First is, are these torque numbers good? I have never been about to get a spec from the manufacturer. I would like to know that I did not cause this issue.
Second, any ideas how I can repair this stripped stud. Ideally I would try to either thread it to M5 or remove it and replace with a grub screw. I have the ability to thread and (if necessary) Heli coil the hole. Advice?
 

jasonhc73

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12 ft/lb is on all my aluminum rack stuff with stainless steel bolts.

For these batteries, I would keep it no more than 15 IN/lbs like you did. These only need to maintain contact snug.


You can try to use a die to take it down from M6 to M5 or add another nut above to have double nuts on the post.
 

circus

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241
I would get a thicker nut. Love the brass ones on the exhaust manifold of my 68 Spitfire. Wish all nuts were twice as thick and brass. First clean up the threads with a die. If your wire end is thicker than the jumpers perhaps you should swap No1 cell with another. More exposed threads that way.
Or you could make a longer buss bar with three holes so the wire end isn't bolted to the terminal.
 
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time2roll

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Not sure how it happened, I have been torqueing these the same since the beginning. I use a torque wrench and set them at 15 in/lbs for general testing and charging and at 20 in/lbs for final assembly.

2 questions;
First is, are these torque numbers good? I have never been about to get a spec from the manufacturer. I would like to know that I did not cause this issue.
Second, any ideas how I can repair this stripped stud. Ideally I would try to either thread it to M5 or remove it and replace with a grub screw. I have the ability to thread and (if necessary) Heli coil the hole. Advice?
in/lbs seems light and ft/lbs would be heavy. Are you sure you are talking inch pounds?

I also would chase it with a die and use a new nut before anything else.
 

CanadianDavid

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Mar 3, 2021
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I should have mentioned. I tried to re-tap the threads with a die and the nut will still not tighten up. The stud does not look seriously damaged, the threads (you can see) are not smoothed off like I would expect. I may have only M5 threads and nut as an option. I suspect the stud was not "right" from the factory.
I would really like to remove the stud and replace with a grub screw, but not sure I can unthread the stud from the terminal. I have also written to the manufacturer, but I find they usually don't know what to say.

Confirmed I use in/lbs. 15 for everything but final assembly, then 20 in/lbs for final assembly.

I also use a tiny bit of dielectric grease to seal it and ensure that the aluminum does not corrode.
 

circus

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I don't think that's a stud.
Shop for a 6mm (or what ever size it is) coupler nut. Theoretically you could use all the treads then make your connections above the damaged post. Safer than a drill and tap!:eek:
 
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time2roll

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That base and bolt is welded on. Pretty sure you would find a smooth flat terminal if you managed to shave off the threaded stud.

I can't imagine how a new nut will not go on if you ran a 6x1 die down the thread. I don't think an M5x1mm pitch is readily available so I think you would be removing more material than is needed to get to M5.
 

NwCali

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Its unusable unless you have a flux capacitor, which I happen to have. Just send it to me so at least it won't go to waste... :)
 

HRTKD

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I also use a tiny bit of dielectric grease to seal it and ensure that the aluminum does not corrode.

If you put dielectric grease on the threads then that could the problem. It acted as a lubricant making the threads slippery and also throwing off your torque settings. I don't have the revised torque settings handy but as an example, with anti-seize grease on threads the torque might have needed to be lowered to only 10 in/lbs. (I'm making that up, to show that you would use less torque)
 

Pyrofx

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Example - Reduction of Torque when Bolt is Lubricated
The maximum tightening torque for a slightly lubricated 1" Grade 5 coarse bolt is 483 lbf ft. Dry bolt torque is approximately 30% higher - or 628 lbf ft.

Tdry = (483 lbf ft) (1 + (30%) / (100%))

= 628 lbf ft

If the bolt is lubricated with SAE 30 oil - the torque compared to a dry bolt is reduced with approximately 40%.

TSAE30 = (628 lbf ft) (1 - (40%) / (100%))

= 377 lbf ft

Note that if torque specified for a dry or slightly oiled bolt torque is applied to a lubricated bolt - the bolt may overload and break
 

HRTKD

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I also use a tiny bit of dielectric grease to seal it and ensure that the aluminum does not corrode.

I would also like to point out that dielectric grease is the wrong product to use in this situation anyhow. A. It shouldn't be used on threads. B. It isn't intended to be anti-corrosive. A forum member recently posted that he had problems with his system after using dielectric grease. He wiped it all off, cleaned the surfaces and used the correct product and the problems went away.

A better product to use is No-Ox-ID or something similar to that.
 
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