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ATL ZJ
03-06-2006, 02:26 PM
Alright engineers out there... How much force is required to shear this? Looking for something to use to make my lower links adjustable. Grade B7, 1" x 12TPI.

Provided that it is good enough to use, can I do any better price wise?

nate
03-06-2006, 03:51 PM
That what most guys I know use, B7 rod.

ATL ZJ
03-06-2006, 03:54 PM
McMaster-Carr. Did a little more looking and it specifies that it has a Rockwell Hardness of C24 and a Minimum Tensile Strength of 125,000 psi.

ILikeMud
03-06-2006, 05:01 PM
That hardness is pretty up there on the scale.
I think you could still sheer it but it would take a hell of a lot of abuse to do it.

BC98
03-06-2006, 08:33 PM
I'd have to dig through my old engineering notes/textbooks, but I think there's a formula that approximates the shear strength of bolt by some relationship with the tensile strength. Just an FYI.

Swamp boy
03-06-2006, 08:41 PM
Thats what I used to make my first set of adjustable arms.. But I used 1/2" and it didnt last long... I rebuilt with 1.5" and had no more problems...

They are GInormously bigger now..:D

JeepinHank
03-07-2006, 10:22 AM
I used 1 1/4" - 12 TPI Threaded Rod for my lower links.

Check out www.blueridgemachinery.com (http://www.blueridgemachinery.com) and go to their e-commerce catalog. Try this link it may work:
http://blueridge.dreamscape.com/bysubcategory.asp?category=Fasteners&supercategory=Threaded+Rod&subcategory=Threaded+Rod+B%2D7+%28Heat+Treated+All oy%29&type=False&specs=True

You have to buy a minimum of 3', but the price is a good bit cheaper. Its better to have more adjustment than not enough.

HTH

ATL ZJ
03-07-2006, 12:52 PM
Thanks Hank, that's a much better deal.

So is 1" rod really too small? The only reason I'm looking at it is because I have Kevin's arms which are 1.5" x .250 wall and the smallest nut I can find for 1" thread is 1.5" OD, so I'll already have to shave 1/8" off it on 2 sides and 2 corners in order to weld it in..

JeepinHank
03-07-2006, 03:48 PM
I don't think the 1" rod would be too small. That's what currie puts on their JJ's if I'm not mistaken. I think it's probably plenty. I went with 1.25" because I welded my threaded rod directly to the housing of my RE joints, and I wanted the little bit of extra surface area.

Either way, it sounds like you're going to have to be pretty precise when you're grinding down those nuts. Not to mention welding them after taking away that much material. Just as an idea - have you considered sleeving the very end of Kevin's arms with a short piece (say 2-3 inches) of 2x2x0.25 and just slapping the insert into that? I know it may look kind of ghetto, but...

Good luck.

BC98
03-07-2006, 04:15 PM
IF your worried about shear strength, it looks like you can approximate yield in shear as half of the yield in tension. Don't know if that'll help ya but I thought I'd post it up anyway.

ATL ZJ
03-07-2006, 05:47 PM
Awesome, thanks for that approximation BC. I'm torn between slimming nuts down to fit into the arms and butt welding a 1 7/8" nut to the end of the arm itself.. Seems like there would be plenty of surface area with a nut that large. I'm leaning towards this option just so I can use the 1 1/4". In terms of surface area on the JJ end, Currie does use 1" rod, but they also weld a notched nut to it.

As for sleeving, ghetto is my middle name. The arms have already been extended 3 inches and sleeved with some 2" .250 wall that Kevin should have used to make the arms in the first place :cool:.

Swamp boy
03-07-2006, 10:12 PM
When I made my adjustable arms.. I welded one nut to the tubing and I put a second one on the tubing so I could use it as a lock nut....

Kraqa
03-07-2006, 10:23 PM
i use 1" grade 8 alloy. i'v had no problems.

ATL ZJ
03-07-2006, 11:03 PM
When I made my adjustable arms.. I welded one nut to the tubing and I put a second one on the tubing so I could use it as a lock nut....

I'm not sure what you mean. If you are talking about using a second nut on the threaded portion to function as a jam nut and prevent rotation of the thread, that's pretty standard. If you meant something else, I lost you...

ATL ZJ
03-07-2006, 11:28 PM
how would you be able to cut the threaded rod with out missing up one side of the threads? but most of the time if use an chop saw to cut it.
Put a nut on it before you cut= poor man's die.

Or go back in with a file or dremel and clean it up if you forget to do the above.

EMTimZJ
03-07-2006, 11:33 PM
Yep, threading a nut on before the cut works great as a chaser to clean up the threads.

Krash80
03-08-2006, 01:39 AM
all my control arms have 1" grade 8 bolts on the ends and that's probably one of the last things I'm worried about breaking...my rig takes a pretty good beating also.

Peak ZJ
03-24-2006, 10:00 AM
Mitchell in our club used Acme threads on his TJ.. never had a problem.. and he beats the piss out of it.