I have an RE adjustable trackbar and am going to replace the bolt at the frame end (not axle end). It is a gold grade 8 bolt, I believe. Now, I understand that grade 5 has a better shear strength than 8, and since the job of a trackbar is lateral which puts lateral stress on this bolt, would I be better off with a grade 5 bolt?
A Grade 8's shear strength is still higher than a Grade 5. :)
Jerry
What part of it causes the grade 8's to snap so easy? Too brittle?
Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT'sJerry Bransford wrote:
this is all new to me, since when do grade 8s snap easily?
I know a few folks that used them in engine mounts and they just shear right off. They would then blow them out of the cast with a torch and try again and again until finally they went back to regular no grade or gr. 5 at the most bolts and the problem stopped.
They are/seem too hard and snap under side impact or shear force.
Same for winch and tow hook mounts.
Mike
The shear strength of a fastener is typically about 60% of its ultimate tension strength. A Grade 8 bolt has a 30% higher tensile strength than a similar Grade
88 Grand Wagoneer
89 Wrangler 00 Grand CherokeeAnd then real life steps in and all the math goes out the window....
Mike
Jim Boucher wrote:
Mike, maybe you got a "fake" Grade 8 bolt but a Grade 8's shear strength truly is greater than a Grade 5. A Grade 5 will DEFORM before it breaks giving perhaps greater warning than a Grade 8 will but it will still snap/shear before a Grade 8 will even begin to deform... but a Grade 8 will not deform as much as a Grade 5 will before it snaps.
Jerry
-- bob z.
"people with less brain power than you are doing more difficult things everyday"©
You never know what the local hardware stores are selling. I didn't buy the things, just saw the results as we are strapping his engine in to get him home.
I see all the charts....
Mike
Jerry Bransford wrote:
When I got my winch, Warn said not to use grade 8 bolts for mounting it because of the brittleness. The directions said to use grade 5 to prevent snapping them off.
Sean
Exactly WHO at Warn said that? If it's in written format from Warn, I'd LOVE to see a copy. That's the one of the stupidest things I've ever heard. I am not saying Grade 8 bolts are needed, they aren't, but Grade 8 bolts sure as hell aren't going to snap before a Grade 5 will. :rolleyes: And my Warn winch instructions sure don't warn against using Grade 8 bolts.
Jerry
-- Jerry Bransford To email, remove 'me' from my email address N6TAY, PP-ASEL See the Geezer Jeep at
I'll look through my stuff, it was in the instruction book, I thought it was weird especially since I had already purchased grade 8 bolts to mount it...cost me another trip to the store.
Sean
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