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COXJ
October 4th, 2004, 20:15
about what is the sheer strength of a 7/16th (grade 8?) it has 6 lines on the top with a u between them. the are greceable so the are drilled about half way threw. then my second question would it be worth it to just ditch the greecable one in favor of a solid one? this is for my single torq arm wich is in doubble sheer withe the load spread evenly. thanks

one more thing is it sheer or shear?

Liam
Bender
October 5th, 2004, 07:13
It's "shear"

Generally the bolt strength in single shear is 2/3 of it's strength under pure axial tension.
In double shear the bolt strength is about 3/2 of it's strength in pure axial tension.

Read this and be enlightened
http://www.rockcrawler.com/techreports/fasteners/index.asp
Dirk Pitt
October 5th, 2004, 07:19
it's also grease not greece. ;)
C-ROK
October 5th, 2004, 08:41
about what is the sheer strength of a 7/16th (grade 8?) it has 6 lines on the top with a u between them. the are greceable so the are drilled about half way threw. then my second question would it be worth it to just ditch the greecable one in favor of a solid one? this is for my single torq arm wich is in doubble sheer withe the load spread evenly. thanks

one more thing is it sheer or shear?

Liam
By my calcs:

A 7/16" Gr 8 has a single shear of 4209lbs through the threads and 6019 lbs through the shank.
The tensile strength is 8118 lbs.

This is for a solid shaft bolt. Drilling out will obviously reduce the values. If you can give me the drilled out hole diameter I could calc the "theroretical" bolt strength by the reduced cross sectional area.
XJJPR
October 5th, 2004, 11:22
By my calcs:

A 7/16" Gr 8 has a single shear of 4209lbs through the threads and 6019 lbs through the shank.
The tensile strength is 8118 lbs.

This is for a solid shaft bolt. Drilling out will obviously reduce the values. If you can give me the drilled out hole diameter I could calc the "theroretical" bolt strength by the reduced cross sectional area.

Man, could you be a little more specific!!!!!!!!1

:D
:D

hinkley
C-ROK
October 5th, 2004, 13:12
Man, could you be a little more specific!!!!!!!!1

:D
:D

hinkley
Hell, calc'n bolt strengths is the easy part. Determining what bolt strength you need is where it get's tough.

Let's see: 38.5" dia tire on 5300lb vehicle with an assumed static friction coefficient of 1.0; total mutlipled torque applied to rear axle of 30,000 ft*lbs; axle retained by 3 attachment points with lower links held at 'theta' angle to the horizontal and upper link held at angle 'phi' to the horizontal can produce a 'static' force of blahblahblah lbs at the tire contact point. Assuming a possible dynamic multiplier of 2.5 means......

Ummmmm, Yup!
You can break everything.
ChicksDigWagons
October 5th, 2004, 18:33
about what is the sheer strength of a 7/16th (grade 8?) it has 6 lines on the top with a u between them. this is for my single torq arm wich is in doubble sheer withe the load spread evenly. thanks

Liam

You're using a 7/16th bolt for a single attatchement point style suspension? Doesn't that seem kinda small?
COXJ
October 5th, 2004, 20:52
thats what i was thinking but it is the setup currie runs on one of his own rigs so i am asuming it will work thats why i ask.

liam
COXJ
October 5th, 2004, 21:00
one other thing this is a currie jonney joint that i am using and by the looks of it i may be able to drill it out to maby 1/2 in. i dont have any experence with jonney joints so yall tell me ya or nay. also 7/16 is the size of the stock hardware that is used on the upper controol arm mounts from the factory.
XJJPR
October 6th, 2004, 04:04
thats what i was thinking but it is the setup currie runs on one of his own rigs so i am asuming it will work thats why i ask.

liam

Are you talking about the upper link on the Currie front three link suspension?

If so they use 9/16" bolts thru the 2.5" Johnny Joints, Not the stock 2" JJ size.

hinkley
COXJ
October 6th, 2004, 05:24
um maby? he uses one upper controll arm on the driver side with a joint that preses in to the cast mount on the pumpkin going to the stock UCA mount. how would he have fit a 2.5 in there? i will call currie tho

WIll
ChicksDigWagons
October 9th, 2004, 05:21
Yeah, thats definately something to double check. 7/16th seems like an aweful small bolt for anything you don't want breaking on you!