i have been trying to get some bolts locally but cant get 8.8 grade in stainless steel (only in zinc). does anyone have some details of a supplier or details of what you used?
cheers

Namrick are pretty good for stuff like this (though P+P can be quite expensive)....

grade of bolts in stainless is different to normal steel. someone will be along soon who knows the equivalent specs...

Ned.

You get A2 and A4 grade..... Not sure how that compares to 8.8 or 12.9

bear in mind stainless is intrinsically weaker than normal bolts- are stainless suspension bolts a good idea???

A4-80 is as close as you can get to 8.8

Table here -> http://home.jtan.com/~joe/KIAT/kiat_2.htm

how does using the weaker stainless affect the sva?

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Originally posted by SyKaTurbo
how does using the weaker stainless affect the sva?

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Anyway, if you use copper slip when installing the bushes etc the bolts tend to get that covered in the stuff they'll never go rusty

I wouldn;t use Stainless of any grade for suspension components, it has been covered a few times, maybe try a search on here?.

Ray

Lots of places were suggested when i was looking for some different bolts in this thread

linky

Never ever ever use stainless in highly stressed applications - it really is that simple!

Dom.

Titanium on the other hand....

You'd need to rob a bank though... I'm sure a member on here told me that he knew a guy who'd spent £2.5k on bolts for his Dax!

i spent 600 on ti bolts for my Z750

can't remember who said it, but it's been mentioned recently.

a wishbone is fastened onto the chassis by a strip of 3mm steel, itself fastened to a 1.6mm wall of RHS. sort of puts it into perspective really.

M12 bolts are massively over-specced. i imagine they're used by all the kit manufacturers now as that's what they can get crush tubes for polybushes in. the original locost design used smaller bolts for the herald metallastic bushes, so a larger dia bolt of lower spec is surely up to the job.

or i may be wrong.....but i'd happily use A4 stainless M12 bolts.
tom

But keep in mind these oversize M12 bolts are there as pivots for M12 rod-ends. While smaller rod-ends are technically strong enough, they wear out very quickly. This is what oversized rod-ends buy you, long life, hence the need for the large bolts.

I suppose you could use small bolts and make spacers for the large rod-ends, but hardly anyone bothers. We're building toys, no F1 cars.

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Originally posted by indykid
can't remember who said it, but it's been mentioned recently.

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quote:

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a wishbone is fastened onto the chassis by a strip of 3mm steel, itself fastened to a 1.6mm wall of RHS. sort of puts it into perspective really.

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Originally posted by another_dom
Never ever ever use stainless in highly stressed applications - it really is that simple!

Dom.

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But if you're talking about the general-purpose stainless nuts and bolts of dubious origin that us mere mortals can get our hands on...
...best left alone for any sort of critical job, IMHO.

Admittedly I have never worked in the oil or chemical industries, though I was a systems engineer at a nuclear power plant for a while! I now work in aviation so consider myself fairly up to speed on fastener design and use. Whilst it is true that there are high grade stainless steels available, they are not best suited for use in highly stressed double shear installations (ie suspension bolts). I certainly would not use the commonly available A2 or A4 grade bolts. No BS

A bolt is only as stressed as the designer wants it to be.

You could use aluminium bolts, if you sized them properly, as any engineer would be able to tell anyone taking an interest.

A 6mm 8.8 bolt will be far less useable than an 8mm A4 in the same application on dry land,....but put them both in salt water and see what happens.


Cheers,
Syd.

[Edited on 28/9/07 by Syd Bridge]

I don't think you can get 8.8 grade bolts in stainless.

never use stainless bolts in stressed areas anyway.

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Originally posted by designer
I don't think you can get 8.8 grade bolts in stainless.

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<snotty post removed>

UPDATE: Syd and I have exchanged polite U2Us - honestly - so this post has been revised...


[Edited on 28/9/07 by David Jenkins]

Nope, no more!

Someone will end up, calling me names, I'll ask where they bought their qualifications, they'll call me an uppity twat or something worse, and I'll tell them to go register at the local college for engineering classes. Then some scotsman will come along and really upset the wagon!!

No, best avoided by stopping things right here. Sorry, you didn't pay for the full argument.

To change the subject, I had a Ca?er?am R260 in my drive yesterday for a while. Not a bad looking piece of kit, but what is that weird oil system all about? Anyone know just how that dry sump system is meant to operate?

Cheers,
Syd.

[Edited on 28/9/07 by Syd Bridge]

...and stop trying to change the argument!

Did Mk not supply you with suitable bolts? Why not use the apprpriate grade steel bolts?

As syd says, you can use whatever bolts you want as long as the correct specs and applications are observed. But i dont see why exotic bolts are needed in these areas. Plated steel should work just fine. A bit of copper slip inside the crush tubes will halt unwanted corrosion.