Installing my new HS9500i. Was a bit surprised that the winch mounts using (4) 3/8", grade 5, course thread bolts. I suppose this is just a FS so I don't rip my frame in half. What do you guys think?

I am not sure but I would imagine it has to do with the strain to failure of the bolt. The grade 5 bolt will have more strain till failuer then a grade 8 bolt. Which means basically that you could probably see the grade 5 bolt start to elongate before it breaks, giving you a warning while the grade 8 tends to be more brittle and gives less of a warning before failure. Plus I haven't heard of grade 5 bolts failing on any winches yet either, hope this helps :D

I thought about changing those 4 bolts on the same winch to grade 8. About .2 nanoseconds later realized that was kinda stupid. The metal case of the winch will more than likely be weaker than teh grade 8 bolts. so why bother.

If it's gonna go anway, I would rather not fubar the case of the winch. at least my next of kin to use it as I go end over end off a cliff. :rolleyes:

Originally posted by mudpup
I am not sure but I would imagine it has to do with the strain to failure of the bolt. The grade 5 bolt will have more strain till failuer then a grade 8 bolt. Which means basically that you could probably see the grade 5 bolt start to elongate before it breaks, giving you a warning while the grade 8 tends to be more brittle and gives less of a warning before failure. Plus I haven't heard of grade 5 bolts failing on any winches yet either, hope this helps :D

Yupyup, what Mudpup said. I've pulled my HS95i to full stall, on one layer of cable, and the grade 5 bolts are still holding. Not stretched, either. Grade 5 is a much better bolt for any application involving shear forces (across the bolt) than Grade 8, because Grade 8's actually have a lower shear strength than Grade 5.

Oh, and even worse, from my standpoint... I lost my little square nuts to my winch sometime in taking it off and putting it back on... so I'm using *ungraded* (mild steel) square nuts (I couldn't get a wrench in to hold 'em, so I had to use square nuts, and the only square nuts I could get, were ungraded) to hold mine on. Not a single slip of the bolts or nuts... but I've pulled the cable off the drum a few times. Oops.

A truly properly engineered setup, shouldn't (theoretically) need anything other than Grade 8 bolts, but Warn can't guarantee that everybody using their winch, is going to mount it properly. Wasn't it 4WOR Mag that recently admitted to having had a winch rip off the mounts on a photo shoot a while back?

Originally posted by Scott@Rockstomper


Grade 5 is a much better bolt for any application involving shear forces (across the bolt) than Grade 8, because Grade 8's actually have a lower shear strength than Grade 5.



Ummm...here we go again?

Originally posted by YellowCJ


Ummm...here we go again?

LOL!!!

The can has been opened.

Originally posted by Scott@Rockstomper

Wasn't it 4WOR Mag that recently admitted to having had a winch rip off the mounts on a photo shoot a while back?
Actually, I think their whole bumper/mount broke away from the frame, not the winch coming off of the mount.

Ummm...here we go again?

Yeah NO SH#T. How many times do we have to go thru this. Grade 5 is not stronger than grade 8 in any category. Search the web if you don't believe me. This is the first site I cam to

http://www.nutty.com/torque_chart.pdf

But, they gave you grade 5 bolts for a reason and the idea about the winch casing strength was probably the reason.:rolleyes:

Originally posted by Trigger

Actually, I think their whole bumper/mount broke away from the frame, not the winch coming off of the mount.

yeah that was in this months rag

but like twaldher said the case is weaker i was putting one on for a friend with my 3/4 impact, and snapped the mount DOH!!!!, any way Warn laughed @ me, and gave me a new one

Grade 5 is a much better bolt for any application involving shear forces (across the bolt) than Grade 8, because Grade 8's actually have a lower shear strength than Grade 5.

Oh boy am I dissapointed to see you say this.

As a "manufacturer" of products, I would have thought you would have known better.

I highly recommend you consult an appropriate text (racing and aircraft fab books are good sources) or a fasteners engineer, do some research, and retract your statement.

Otherwise your credability / reputation is going to suffer.

I'm WAAAAY too tired of correcting this silly misconception.

HINT.....no same size gr 5 bolt is greater in shear strength than a Gr8...and shear strength is directly related to UTS !!

http://www.americanfastener.com/techcharts.htm

Just more accelerating reading.

MJ:rolleyes:

Yeah right Bill, that's like saying a solid rod is stronger than a tube. Duh! lol.

So why did my class V hitch (1400lb TW 10k CW 14k WD) come with grade 5 hardware hmmmmm? Dont think it was to make it any cheaper.

Before every one starts talking out their a%%^&ss , do a search quit wasting your grade 5 breath !!:mad:

So why did my class V hitch (1400lb TW 10k CW 14k WD) come with grade 5 hardware hmmmmm? Dont think it was to make it any cheaper.

Nobody's saying Grade 5 isn't up to the task....it all depends. But there's just no way a grade 5 has greater shear strength thean a Grade8, and there's no way a Grade 5 will bend where an 8 will break. The 5 will bend and break before the 8 - no question. But...there may be a larger gap between bending and breaking for a 5 than for an 8. It's all been explained before.

Originally posted by BillaVista


Nobody's saying Grade 5 isn't up to the task....it all depends. But there's just no way a grade 5 has greater shear strength thean a Grade8, and there's no way a Grade 5 will bend where an 8 will break. The 5 will bend and break before the 8 - no question. But...there may be a larger gap between bending and breaking for a 5 than for an 8. It's all been explained before.

Actually Bill, that was exactly my point :D things are spec'd for a reason.. typically because it's within spec.