lexi
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| posted on 10/4/05 at 04:44 PM |
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bolts for suspension bushes
Hi Guys
I`m picking up on my book Locost build after 2YR layoff due to other projects. Where was I? Yeah I have 9.5mm bolts which go through my Herald
bushes.On the head of the bolt it reads ORSB1 S1. Are these bolts strong enough as I`ve made all wishbones etc. Started this project 4yrs ago and am
amazed how it has all moved on as far as availability of suitable components goes. I spent an inordinate amount of time making stuff that you can buy
so cheaply now.
Thanks in advance
Lexi
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whpracer
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| posted on 10/4/05 at 05:52 PM |
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always good to pickup the past,
bus please consider to go for PU bushes
unless you'r willing to chance the herald one's every year because the wear out very fast
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lexi
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| posted on 10/4/05 at 06:40 PM |
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Thank you my young Dutchman! Yeah I`m not a fan of PU and i would have to change steel bushes at the end of my wishbones panhard trailing arms. I know
that bolts are coded for strength and wondered if anyone knew the meaning of the code on my bolthead. Been that long since I bought them.
Alex
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Marcus
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| posted on 10/4/05 at 06:47 PM |
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Nice to see another crossflow on its way. Re bushes, you probably have 3/8" UNF bolts through the bushes, as for the markings, can't help
I'm afraid.
I dont think you're stuck with rubber bushes though, I've seen replacement Herald bushes in PU from Supaflex I think.
Marcus
Marcus
Because kits are for girls!!
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niceperson709
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| posted on 10/4/05 at 09:43 PM |
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Hi mate
If in doubt replace them with Hi tensile bolts and or contact your local fastner suplier he will be able to tell you what grade of bolt that you have
.
best wishes
Iain
Best wishes IAIN
life is not the rehearsal , it's the show so don't sit there thinking about it DO IT NOW
http://iainseven.wordpress.com/
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JamJah
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| posted on 10/4/05 at 11:51 PM |
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5th thread along simular lines in a week. I bought 20 PU bushes, from TRGB links on a previous thread just add .co.uk though for less than £80 with
vat and shipping. standard herald replacement so will fit.
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lexi
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| posted on 11/4/05 at 09:05 AM |
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Thanks guys
Top forum!!
Lexi
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clbarclay
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| posted on 11/4/05 at 09:12 AM |
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Is ORSB1 S1 the only identification on the head, is there no other markings like lines or numbers?
The common markings are a number of lines radiating out (eg 3 lines going out from the center) or a stampes number with one decimal place (eg 8.8 or
10.9).
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Rorty
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| posted on 12/4/05 at 04:05 AM |
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Every high tensile bolt sold in the UK should have a marking on its head; if it's a plain head do not use it.
The markings can consist of either letters (UNC, UNF and Whit. threaded bolts) or numbers (Metric or ISO Metric). The letter to look for is
'S' or a higher letter(imperial), or the numbers 8.8 or higher (metric).
For the technically minded, the 8.8 designation is two separate numbers. The first '8' is the tensile strength, i.e. the load at which the
material begins to fail, given in units of 100MPa or MN/m2, giving 800 MN/m2 or 800,000,000N/m2. Convert this to kg by dividing by gravity (9.81m/s2)
say 10, to give 80,000,000kg/m2, and then divide by 104 to convert to cm2 which gives 8000kg/cm2 or 8 tonnes/cm2. The second part of the designation
'.8' is then used to generate a decimal fraction of the first part, i.e. 8 x 0.8 = 6.4 or 640Mpa, 6.4 tonnes/cm2. This is the yield
strength, i.e. the load at which plastic deformation of the material occurs.
Stainless steel bolts usually have a tensile strength of 5 Tonnes/cm2, 33 tons/in2 (marked A2 for Stainless Steel and 'M' for the
strength) so be warned! Some bolts may be marked in Newtons per square centimetre, in which case high-tensile means over 80N/cm2. Do not get confused
with the manufacturer's name code, e.g. GKN, SN, BP, etc.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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David Jenkins
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| posted on 12/4/05 at 07:22 AM |
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Although it is a good and worthy thing to buy the very best quality bolt for the job, aren't we overlooking one very important factor?
The suspension arms, bolts and bushes are held onto the chassis with pieces of 50mm wide, 3mm thick mild steel strip. From the rim of the bolt-hole
to the edge of the steel strip is probably 10 - 15mm. I would suggest that this steel strip is likely to fail long before even a middling-quality bolt
gives up.
At a guess, I would suggest that what we should be looking for in a bolt is toughness, i.e. a resistance to shocks and a lack of brittleness.
It is certainly a good idea to buy good quality bolts from a known supplier as there are a lot of Far East bolts around that are pretending to
be high-quality items, but may well prove to be treacherous in use.
For more info, see Carroll Smith's book on bolts & fasteners, or read the stories about aircraft crashes caused by 'cheap'
fasteners that failed in service.
For myself, I bought 'AN' quality nuts and bolts from a reputable aircraft parts supplier (partly for 'known source' issues,
but also because I was able to specify the length of the unthreaded shank). Otherwise, I would have looked for big-name branded products from an
engineering supplier.
rgds,
David
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JamJah
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| posted on 12/4/05 at 10:50 AM |
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Was plucking up currage (spelt wrongly) to ask this anyway, but what is the tensile rating of an A4 SS bolt, and how does that compare to an 8.8 HT?
Bearining in mind the SS shouldnt rust.
Even though rorty has been opinionated in his choice of cars, he comes in handy! Cheers for all the info guys, made a daft question very easy to ask!
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flak monkey
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| posted on 12/4/05 at 11:08 AM |
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See this handy little table for tensile strengths of stainless bolts
http://mdmetric.com/fastindx/t28u.pdf
Sera
http://www.motosera.com
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JamJah
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| posted on 12/4/05 at 11:37 AM |
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Call me thick, but what does that mean?
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Rorty
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| posted on 12/4/05 at 02:10 PM |
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quote:
Originally posted by JamJah
Even though rorty has been opinionated in his choice of cars....
Pardon?
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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David Jenkins
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| posted on 12/4/05 at 02:15 PM |
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INCOMING!  
quote:
Originally posted by Rorty
quote:
Originally posted by JamJah
Even though rorty has been opinionated in his choice of cars....
Pardon?
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JamJah
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| posted on 12/4/05 at 02:36 PM |
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Thought you got in trouble with the catherham forum. Wasn't having a go. Guess no one actually knows what that table means.
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flak monkey
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| posted on 12/4/05 at 02:46 PM |
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The table has quite a bit on it you dont need to know.
You are really only interested in the steel grade (second column) and the tensile strength in the bolts column.
Tensile strengths of stainless bolts vary from 500 to 1000N/mm^2 depending on the exact material.
For your bolts 316SS A4 the tensile strength is about 700MPa. Compared to 8.8 steel bolts which are about 800MPa as Rorty said. Not a huge
difference...
(See the chart here: http://www.assda.asn.au/asp/index.asp?pgid=18732)
David
[Edited on 12/4/05 by flak monkey]
[Edited on 12/4/05 by flak monkey]
Sera
http://www.motosera.com
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