Stainless Steel bolts vs. regular grade 8

[Neal Molder]

How many you guys have used stainless steel ARP grade bolts? If so how did look. Did you like working with them? I'm thinking about using them on everything.

[1968SWBBigBlock]

Not all stainless bolts are created equal.
Arp uses a special hardened alloy for thier and they are over kill for most everything.
ARP makes a great product.
Most of the bolts that we use are not nor do they need to be grade 8.
Grade 8 is normally reserved for shock bolts, leaf spring bolts, motor mounts, tranny to engine etc.

[toddtheodd]

I use grade 8 for almost everything (though I did get ARP for most of my motor that I am building right now).
Grade 8 doesn't rust, and is strong as all hell... why use something weaker? Every time I have a bolt break, or fall out, I replace it with grade 8.

[mclairmo]

I used grade 8 from Napa or other sources for everything. I heard stainless is more brittle.

[cdowns]

grade 8 bolts are mostly a waste of money and not needed in 99%of applicatiopns that they are used
i use marine grade stainless whenever whereever possible a little time with the buffer and they shine purtty/i buy in bulk at local nut and bolt shops

[rwolf9653]

I generally use grade 8 on anything associated with drivetrain or undercarriage. All else I use grade 5. Tractor Supply Company (TSC) has been a good and affordable source for bolts and nuts. They have a fixed price per pound and you can mix or select whatever you want.

i use marine grade stainless whenever whereever possible a little time with the buffer and they shine purtty/i buy in bulk at local nut and bolt shops

Do these resist rust any better in your experience. They would be great on my off road vehicles if they do.

[cdowns]

Originally Posted by rwolf9653

I generally use grade 8 on anything associated with drivetrain or undercarriage. All else I use grade 5. Tractor Supply Company (TSC) has been a good and affordable source for bolts and nuts. They have a fixed price per pound and you can mix or select whatever you want.


Do these resist rust any better in your experience. They would be great on my off road vehicles if they do.

no rust when used in longterm saltwater enviroment is what sold me on these many years ago

[rwolf9653]

Originally Posted by cdowns

no rust when used in longterm saltwater enviroment is what sold me on these many years ago

Sounds great. Thanks!

[LONGHAIR]

Originally Posted by toddtheodd

Grade 8 doesn't rust, and is strong as all hell... why use something weaker? Every time I have a bolt break, or fall out, I replace it with grade 8.

Other than a zinc plating to somewhat resist rust, there is no reason at all to think that the higher grade makes it any more rust proof.
That same zinc plating is available on nearly every grade of bolt, so a grade 8 is no better than a grade 5 in that respect or even a grade 2 for the matter.
Most guys only concern themselves over the bolt anyway.....they forget, or never knew, that they should be using grade 8 nuts and in most cases flat washers too.
The price starts to catch-up to you at that point. Hardened nuts are quite a bit more expensive and the hardened washers ever more yet.

The real issue here is "what you get for your money" and "what is this bolt really doing?"
Having a bolt that is "ten times" stronger than the item to which it is attached.....is overkill. ($$$) So what is the point? the bracket (or whatever) breaks before the bolt....what have you gained? nothing.
Do you need a grade 8 bolt threaded into an aluminum part?....no
Suspension parts like leaf spring mounts or 4-link mounts....sure, this is the place where a little more can't hurt.

You really have to be careful with stainless steel bolts/nuts. Generally you need some kind of lubricant to combat "galling/seizing". This can be a problem when assembling or dis-assembling.





BTW, a bolt that "fell out" was not because it wasn't strong enough...it just wasn't tight enough...

[Neal Molder]

Great thoughts guys !! I've read about the hole stainless thread galling thing. Which kind of worries me. If i use antiseize and correct torque, whats to say my bolts won't seize over time. My interest with stainless is purely for cosmetics and wow factor. I've heard that if you use a pure stainless steel bolt with a steel alloy nut, that thread galling is less likely to occur. If this is true won't the nut start rusting in few years. That kind of defeits the purpose doesn't it.
I guess i like to here from a experienced hotrod guy to learn from his blood sweat and tears. I mean do their pros outway the cons , when it comes to a show truck. Is it worth wiping a rewiping antiseize lubricant off everything? Is it worth the pain in the ass? and finally will i look at my undercarrage when its done and say. "Those are fasteners are cool!!!!"

[cdowns]

i've had no issues at all taking stainless hardware apart after 35-40years cant say the same about hardened steel tho// if anything i'll just put a thin coat of white grease on stainless during assembly

[nicolas72gmc]

I would use grade 5 on pretty much everything except engine and drivetrain. The tensile strength between the two isn't that significant when you're talking grade 5 vs. grade 8 with tensile strengths of 120,000 psi vs. 150,000 psi respectively, what is the diff.? I seriously doubt you'll exceed the yield strength which is a little less for both grades if they are torqued properly (unless you're in a wreck or something like that, then it is not gonna matter anyway). The grade 5 will stretch a little more before it breaks and someone said it too I think, lubrication does help on some types of alloys but it changes the torq specs too. We had a big class about this at work, had a bolt expert from fastenal come in. We were talking about bolts 2" to 6" diameter though, but it is all relative. peace.