Funonthefarm
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Stainless or zinc coated bolts?
- Thread starter Funonthefarm
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JUKE179r
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I prefer nickel anti seize but that's me in my little weird world.
trigga72
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The proof strength of even A4-80 is 10% lower than an 8.8
I.e. 660 mpa for 8.8's. 600 mpa for A4-80's Does it matter ? You be the judge
A270's are massively weaker at 450 mpa
Yes the “proof” strength is lower, but the yield strength is roughly the same. How often do you tighten any bolt up to its proof, or yield, strength?
I don’t necessarily think stainless is “better”, but having done a full rebuild on my 27 year old 110, I fitted all stainless to make sure I didn’t have the **** on with seized nuts and bolts if I need to replace anything in the future.
Each to their own, but to say stainless is weaker, as has been said several times in this thread, is misleading. If you want to fit them, YRM are the only supplier of A4-80 in kits that I know of. Most others are only A2-70. Don’t fit A2-70 to anything other than trivial stuff, like lights, grills, non structural items.
Funonthefarm
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Before we get distracted with Mpa and yield strength - Can someone put forward the rationalisation as to why SS is better and the benefits? if this could be done in comparison to the galvanic difference, cost and benefits this would be really helpful. ATM there is all conjecture.
Funonthefarm
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So fundamentally we are saying that SS is literally just to make it easier to remove in the future.
On a galvanic reaction basis and a new galvanised chassis - please correct me if I'm wrong:
SS will:
React with any Ally parts and eat them first -
React with the zinc galvanising and eat that, then it will finish by eating the steel below.
With zinc bolts - it would go:
Ally eats zinc, then the steel below eats ally at a slower rate - so theoretically should extend the time for corrosion.
Zinc technically should not not react with the galvanised chassis
Zinc to steel - zinc goes first.
So other than the fact SS shouldn't corrode hugely on its own - it will fundamentally be the most noble and react with every other part it comes into contact with?
trigga72
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It's not just how many times you tighten it though. When a bolt is used where it is constantly being loaded up i.e. Suspension or say on a tow ball it becomes a bit more dodgy. Bodywork absolutely fine.
When have you ever seen a manufacturer put stainless bolts on a tow ball ? It doesn't happen ever !
I worked in the nuclear industry until last year and worked with stainless fixings and material pretty much every day . I can tell you myself and all my colleagues will all say stainless bolts are like putty strength wise , even A4-80's .
Entirely upto you what your landy is held together with , I'm not arguing.
My 90 has a lot of stainless for the bodywork fixings but no way would I use them for suspension. My winch is held on with 12.9 capheads
Gluv
If you look at my defender, you will see it has no stainless anywhere near the tow ball, and if you search my posts, you will see that I actually advise AGAINST using them in specific areas such as the tow bar.
I would never advise fitting a winch, or a winch bumper intended to be used with a winch, with stainless fasteners. I think your missing the point. I’m not saying they are the “use anywhere” answer to rebuilding defenders, far from it. They have a use, and people will use them for it, some will use them in areas they shouldn’t, but that’s not for us to decide.
I have never questioned you, or your colleagues, qualifications, so saying you worked in nuclear makes out like your trying to justify what your saying?
Yes, in my application, I have used them solely for the ease of removal. I can’t answer for anyone else’s reason for using them.
As for the galvanic scale, have a read of this.
https://www.bssa.org.uk/topics.php?article=89
I would also like to point out, that when I advise people on rebuild threads, I advise using some form of “isolator, or gasket” between the materials. This, combined with extra earth wires, should completely prevent any sort of bimetallic corrosion.
trigga72
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Not really, I'm just saying that in my particular industry, stainless fasteners are used on a massive scale . From experience I wouldn't use stainless for anything that would have an effect on safety or the integrity of the running gear. As I said earlier, I use stainless on visible body fixings myself
Gluv
Funonthefarm
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Thanks for the reply, would be really useful if you could advise on where you think it’s useful. As I’m about to start the re build, I am just trying to find out what’s best. It just seems that a lot of people “put SS in” and obviously a lot of suppliers like yrm only offer SS... and I was going to buy all SS. So this is a fact finding mission to make sure I’m not doing anything stupid and just popping expensive SS in for the sake. The difficulty is that there is no information as to what or where is best to use them etc...
So anything you can help me with would be more than appreciated.
trigga72
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frog hopper
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Coppa slip is the work of the devil, a tiny drop the size of a grain of rice, on your overalls will magically find it's way all around the house, especially on that expensive wall covering the doris just had to have.
I read the comments about protecting between SS and other materials by the use of protective gaskets and the like, what would be used to protect the internals of the hole the fixing is going through??
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A bloke I know who rebuilds helicopters on his drive (!), helicopter engineer, obviously, has to use bolts that are stupidly expensive. Sometimes he gets a ton extra, so he flogs them to us (cheap) and we really apreciate them cos they is pretty as well as fu ck off strong. Don't know what they're made of and can't be rsed to go and find some out the garage to look at the head. Any helo engineers on here? Anyway, on a kit car where stuff is often visible, it helps if they is pretty and man enough for the job.
I think people make thin plastic gaskets from 5 litre containers or heavy polythene, and it just slots between the alloy surfaces, ie front wings to grill panels etc
Have no idea how effective it is, and it might be overkill? I can see the seatbox to body/sills being a good places for them.
To separate aluminium and steel I've used the A4 (paper size, not SS grade) plastic covers that you often get on the front of bound documents - you can fashion a separation gasket in any shape and use hole punches on the bolt holes. They're hard wearing and totally transparent. Had some on my rear doors now for 10+ years.
IMHO re SS/ tensile steel - anything graded high tensile 8.8 or above should stay that way. Run of the mill body bolts can be SS no problem.
IMHO re SS/ tensile steel - anything graded high tensile 8.8 or above should stay that way. Run of the mill body bolts can be SS no problem.
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