Stainless bolts

[jasst]

Actually got around to doing my rear tie rods today, with the kit supplied by Craig Waterman, as I had to check for anything obvious re my suspension prob, so as the bolts that hold the wishbones on were well corroded, I thought I would pop in to my local fastening supplier and get some stainless ones, he asked what they were for, and when I said suspension , he cautioned against using them for this, as apparently stainless bolts are more brittle, and could crack! so it looks like the old ones with new nylock nuts will be going back in. Incidentaly, in light of the problems other forum members have had doing this job, I couldn't quite believe how easily the adjusters came out of the wishbones, no heat needed, just a 3/4 drive socket set and a 4' length of water pipe! perhaps my regular spraying with wd40 over the last couple of months has done some good!

 

[alfatwo]

Never use stainless fixings or anything cheapo for load bearing stuff, the origin spec is found stamped on the head of the bolt.. you can look it up!

Dave

 

[Ebenezer]

Umm - I take it then that wheel bolts are not considered load bearing? Which I guess is true sort of. However there must be some lateral forces when turning.
Eb

 

[jasst]

Never use stainless fixings or anything cheapo for load bearing stuff, the origin spec is found stamped on the head of the bolt.. you can look it up!

Dave

so what about the stainless wheel bolts that were available on the forum? just interested if its a fact that stainless is weaker.

 

[CatmanV2]

Umm - I take it then that wheel bolts are not considered load bearing? Which I guess is true sort of. However there must be some lateral forces when turning.
Eb

Not really. The bolts are to clamp the wheel to the hub. The turning force is transmitted across the hub / wheel interface.

At least that's my understanding (and assumes your bolts are tight)

That's how it's been explained to me.

C

 

[CatmanV2]

so what about the stainless wheel bolts that were available on the forum? just interested if its a fact that stainless is weaker.

It's not inherently weaker, it's about selecting a material that has the correct (suitable) combination of properties for the given application.

C

 

[alfatwo]

That correct C.. you can also use aluminium or titanium for lightweight clamping loads..

On production cars though its best practice to use the manufacture's original spec when choosing fixings..

Lets face it Fiat didn't spend 100's of Thousand's on Maser R&D then decide to source the fixings from your local hardware store!


Dave

 

[BennyD]

No, they got the wishbones from the local hardware store. Except they didn't spend 100s of 1000s on R&D. I think they knocked them up at the local comp during the dinner hour.

 

[zagatoes30]

Lets face it Fiat didn't spend 100's of Thousand's on Maser R&D then decide to source the fixings from your local hardware shop!


Dave

No it was only the wishbones they bought from the local chocolate factory

 

[zagatoes30]

Arghh spooky posting the same comment as benny at the same time

 

[Felonious Crud]

Arghh spooky posting the same comment as benny at the same time

More terrifying than spooky.

 

[Navcorr]

The hub / wheel interface is critical. Under static load I don't see a problem with SS. Dynamic load is potentially a different matter. SS is not as ductile as mild steel i.e. SS is more rigid. Why is this a possible problem - imagine hitting a pot hole at speed. The sudden increase in stress will not transfer across the hub and the bolts could be subject to shear forces beyond their elasticity. If the bolt undergoes sufficient plastic deformation it will fail.

Odd words to use for a metal maybe. Under sufficient load a metal will change shape or deform. A temporary change of shape that reverses after the load is removed is elastic deformation. When the stress is sufficient to permanently deform the metal it is called plastic deformation. Go too far into the plastic region and failure occurs. This is more likely to occur with a SS bolt.

I can see the aesthetic advantage of SS bolts. Personally I wouldn't touch them with a barge pole. One preferably made of wood

 

[alfatwo]

No, they got the wishbones from the local hardware store. Except they didn't spend 100s of 1000s on R&D. I think they knocked them up at the local comp during the dinner hour.

Stop making silly comments again Ben... All Maser components had to pass an EU stringent safety check when new. and they did!

Here lies the problem, after three years down the line when the car was out of warranty you were done, let alone 16 years later...

I just put it down to old car stuff and get on with it I just love em..

Dave

 

[ANY]

I here found a simple and good guide to your question regarding switch to stainless bolts:
http://www.volksbolts.com/faq/basics.htm

A "standard" bolt is typically of 8.8 quality. For higher loads, which could be the case for suspension components 10.9 or even 12.9 can be used. See marking on bolt head.