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Discussion Starter · #1 ·
After much research, I learned that Grade 5 bolts actually have greater shear resistance than grade 8...apparently the hardness of grade 8 makes them more prone to shearing, whereas the slightly softer grade five will give and take a little bit...although Grade 8 win out hands down in tensile strength. So I bought some 3/8 Grade 5 threaded rod, red locktite, and nylock nuts, and cut some 2.5" studs, locktited end that goes in the hub, and nylocked the outer hub on...Seems to be pretty HD.
Dean

1977 CJ5, 304 V-8, Welding Improvements Galore!
 
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Discussion Starter · #2 ·
The part of this idea that leaves me wanting a little more, is not so much the grade-5 vs grade-8 'issue', but the fact that you used 'all-thread'. This is also a problem with the (grade-5) fasteners that come shipped with some new hubs, or the fasteners used for stock hubs on Jeeps in the 70's or 80's. It seems to me that 'everyone' has forgotten what the fasteners looked like that came with the stock hub-flanges, or, even some aftermarket hubs, in the 60's, and back. I've saved some of those old bolts, for reference. The feature that I like about the 'old-way', is that there is a 'shoulder' on the fastener, that 'bridges' the gap at the hub-to-hub interface. Look close sometime, at the entrance to the hole in your vehicle hub, where the threads are. The threads do not come very close to the hub surface... In fact, I believe you will find the threads start about 3/16ths, or 1/4-inch recessed. Back in the 40's, 50's, 60's, the Jeeps came new, with a 'sort-of' special bolt, that had a shoulder long enough to protrude into the vehicle hub, and 'bridge-the-gap'. So, today, when I am 'doing' hubs for myself, I either modify bolts, or make studs, that incorporate this shoulder-feature. If I am using bolts, I simply buy 'top-quality' US bolts that are a little too long, like 3/8ths-16 x 1.75-inch. Then, when I cut them down to 1.375-inch, I am left with a shouder that approximates what the 'factory-original' looked like, many years ago. In my opinion, this bolted joint seems to want to 'work' a little, anyway, and nothing I seem to be able to do, stops it from 'working'. And, I feel that the 'shoulder' does a better job of carrying 'shear-loads', than a 'threaded' section.
Just my thought... just an opinion.

bob
 

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/wwwthreads_images/icons/tongue.gif I agree with Bobbikins 100,000 percent. All thread ain't a stud; doesn't do the same job; never will do the same job; will wear out the hole; will shear easier; probably isn't even grade 5 because they can't thread it easy if it is, and we all know that they don't want it to take long; and whoever said grade 5 is more shear resistant than grade 8 hasn't been to school. Grade 5 resists STRETCH a little better, but in direct shear there's no comparison. Whew! I guess that's all the bad things I have to say on this. Sorry Farmjeep; I wish it could have been a better report./wwwthreads_images/icons/frown.gif

CJDave
 
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Discussion Starter · #4 ·
CJ... Yeah.... I'm a little skeptical on a couple of points in the original post. For example, I work in an area where I deal with lots of fasteners, especially high-strength, A286, aircraft, NAS, and some MS fasteners. Occassionly we use some grade 5 or grade 8 fasteners, and we have even used a little 'all-thread'. I have never been aware that all-thread is available in grade 5. The 'stuff' we get is all very soft, like grade 1 or 2, commercial quality. So,.. I assumed that 'Farmjeep' must have learned something about all-thread that I was unaware of.
And, the other thing that I am skeptical of, is the comment about grade 5 shear being greater than grade 8 shear. I have looked in the info that I have on this, and all I see is a listing of shear area, for various size fasteners, and the minimum allowable strength, either ultimate single shear, or 'working'. Anyway I want to look at this data, the grade 8 will carry more shear than the grade 5. 'Course, the grade 5 is more 'ductile', and the grade 8 is more 'brittle'. So perhaps Farmjeep is referring to the ability of the grade 5 to be a little more 'forgiving' before it breaks.
If the 'topic' 'hub-joint' were an exercise 'of-convention', meaning, that if we could count on the fastener providing the clamping load, and friction carried the shear, then the grade 8 would 'win', hands-down. We know this is not the real-world situation.

bob
 

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/wwwthreads_images/icons/tongue.gif I am totally in favor of the stud having full, unthreaded diameter in the counter bore as I am sure the designers intended. That, I would think, is a very important feature of the system../wwwthreads_images/icons/smile.gif

CJDave
 

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i've seen my neigbors (dirt-track circle racers)drill out and tap all thier rotors/axles and install 5/8" screw-in studs on every car they work on, i think they are considered "heavy duty", they also make 1/2" studs, check-out this link

http://www.rsracing.com/rscatalog/asppages/whl-stud.asp

3/4tonYJ
/wwwthreads_images/icons/cool.gif'89YJ,4.3/th350/np231/8-lug,44/60
 
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