gulf zxr
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| posted on 12/1/07 at 07:29 PM |
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Are A2 stainless steel bolts OK for Suspension Mounts?
Hi Guys,
Just about to start sourcing nuts and bolts, M10x70mm for my suspension. Question is, are grade A2 stainless steel bolts OK for this purpose?
Thanks Gulf ZXR
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Wadders
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| posted on 12/1/07 at 07:35 PM |
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Not really recommended, as their not high tensile, you could really do with at least 8.8's for suspension use.
]Originally posted by gulf zxr
Hi Guys,
Just about to start sourcing nuts and bolts, M10x70mm for my suspension. Question is, are grade A2 stainless steel bolts OK for this purpose?
Thanks Gulf ZXR
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Ian D
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| posted on 12/1/07 at 07:39 PM |
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http://home.jtan.com/~joe/KIAT/kiat_2.htm
Have a look at this Site. I thought they needed to be a minimum of 8.8 metrics.
Ian
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gulf zxr
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| posted on 12/1/07 at 07:46 PM |
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Thanks guys, looks like it's grade 8.8 then...
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t.j.
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| posted on 12/1/07 at 08:34 PM |
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quote:
Originally posted by Ian D
http://home.jtan.com/~joe/KIAT/kiat_2.htm
Have a look at this Site. I thought they needed to be a minimum of 8.8 metrics.
Ian
Interresting!!!
Always thought that A2-70 was as strong as 8.8.
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iank
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| posted on 12/1/07 at 08:49 PM |
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So it looks like A4-80 would be possibly acceptable, though the yield strength is a little less.
But I'd stick with 8.8's myself, simply as it's one less thing to have to justify to the examiner.
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SixedUp
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| posted on 12/1/07 at 11:07 PM |
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Never mind the examiner ... you really really don't want the suspension parting company with the car at speed in mid-bend.
I was always told to never use stainless where strength was required. On that basis 8.8 or 10.9's seem like a much safer option.
Cheers
Richard
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iank
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| posted on 12/1/07 at 11:29 PM |
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well indeed, but the A4-80's have the same tensile strength as 8.8's. They aren't the ordinary stainless bolts you see in large
bins at shows.
If you get anywhere close to either yield strength of the bolts your suspension is shockingly badly designed or you've kerbed it very hard.
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Chippy
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| posted on 12/1/07 at 11:44 PM |
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Had stainless bolts holding my screen and roll bar. SVA man failed them, (along with a few other things), so had to replace them for the re-test with
8.8's. Ray
To make a car go faster, just add lightness. Colin Chapman - OR - fit a bigger engine. Chippy
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flak monkey
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| posted on 13/1/07 at 10:22 AM |
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If you work out the shear strength of an M12 stainless bolt it is well above what is required of the suspension mounts on a locost - whether it be A2
or A4 grade.
However stainless is prone to fatigue (not a good thing on a bolt which essentially is covered in stress raisers!). so may lead to a premature
failure, not due to overloading.
You could quite safely attach the suspension to a seven type car with 12.9 grade M8 bolts and they would not break, but for some reason that just
doesnt 'look' right, and for people in their sheds much of it is whether it looks up to the job...
David
[Edited on 13/1/07 by flak monkey]
Sera
http://www.motosera.com
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andylancaster3000
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| posted on 13/1/07 at 12:23 PM |
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The other thing that you have to think about is the metal work it is attached to. I really wouldn't expect an 8mm 10.9 bolt to fail before the
brackets have given up. If you are ever in the situation where such a bolt fails i think it's the last thing you're going to be worrying
about!
[Edited on 13/1/07 by andylancaster3000]
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