Bolt grade ??

[broncodan1]

Hey,
I was putting in my intermediate housing and tranfer case
using grade 5 bolts. My buddy said I should get grade 8
bolts. Now he's got me thinking about it! Or should I say
worryin' bout it...! Any imput would be greatly appreciated.
Thanks,
Dad

 

[SteveL]

I use grade 8 for all that stuff. Helps me sleep better at night.

 

[SaddleUp]

You'll never need the extra strength of Grade 8 bolts for that application so there isn't any reason to worry. Grade 8 bolts do have places that are appropriate but there are also a lot of places where they are not appropriate as well. Under extreme stress a grade 8 bolt will break where a grade 5 will either bend or stretch. Grade 8 bolts are also harder to drill out if they are broken off. In some cases (such as yours) the surrounding material is already weaker than a grade 5 bolt so a grade 8 bolt isn't going to give any advantage. I doubt it will hurt anything though. (Either one will strip the casting threads if they are over torqued)

 

[Steve]

This subject has been beat way past death on Pirate and another board I'm on. SaddleUp is correct, you don't need Grade 8, especially in that application. Not convinced? Consider that Warn supplies Grade 5 bolts to attach their winch to the winch plate. There's only four bolts holding the winch on. Warn's instructions specifically say to NOT use Grade 8. Ever hear about a winch coming off of a vehicle because the Grade 5 bolts broke? Me either.

 

[HotWheels]

grade 5 is fine...I still used grade 8 just about everywhere cause I get them for a great price. I used Stainless Steel and Grade 8 everywhere. I hate rust!!

 

[broncodan1]

Hey,
Thanks for the imput!
Dan

 

[HotWheels]

Hey,
Thanks for the imput!
Dan

You're very welcome. Have a good one.

 

[rob wilson]

I'm guilty of using Grade 8's in a number of places myself. Had not considered the strech vs. break issues of the harder grade 8's. I've also used a lot of stainless fasteners. Mostly non engine/drivetrain. Any issues with dissimilar metals between stainless and the rest of the metal/rust on a Bronco?

 

[elemetal]

The problem with ss bolts is they are soft (tough) but not brittle (hard). This makes 'em easy to drill out but also makes 'em easy to bend, round off corners or round out allen heads. They have their place, but they are about 90 to 110 kpsi tensile strength rather than 140-190 kpsi of the typical "steel" fasteners.

I seem to remember that annodic corrosion between steel and stainless isn't that bad, something to do with how far apart the base metals are from eachother on the periodic table. Maybe someone else is more clear on this...

 

[broncobilly_69]

The guy at Tacoma Screw Porducts told me stainless bolts are rated as a grade 2.

 

[HotWheels]

The guy at Tacoma Screw Porducts told me stainless bolts are rated as a grade 2.

Hmmm...anyone else? I know some of the guys there know their stuff and some don't...kinda like here...

 

[rob wilson]

Good info Jeepster! Thanks.

(Never thought I would say that to anyone with "J***" in thier name.)

 

[HotWheels]

Yeah Jeepster, thanx for the info/website..

 

[Mark]

Yeah Jeepster, thanx for the info/website..

What info/website?...?
Did Jeepster post something on this thread? Why don't I see it?

 

[68ford]

ive had some places tell me i should run f-11 hardware because its so strong,all race trucks use them, but then i realized how much they are i usually just get grade 8 from home depot or wherever kinda just by instinct because im used to just grabbin the gold cad plated ones.

 

[HotWheels]

What info/website?...?
Did Jeepster post something on this thread? Why don't I see it?

Jeepster is deleting his posts....go figure.

 

[73stallion]

i have stainless bolts in my intake and it makes me nervous when i torque it down.

 

[SaddleUp]

Jeepster is deleting his posts....go figure.

Either that or there is a glitch in the board. I know for certain I read it after he posted it to be sure the information looked accurate.