3200 Taste Police - Opinion Needed!
- Thread starter Sniffer
- Start date
No I'm not anyone called V Bird. I am new to the Maserati marque.
Sprogs, I'm not having a go, just giving some subjective opinion. I am quite happy for you to disagree and I won't be upset. If people have all the facts, then they can make their own risk assessment.
As a note to you personally, I would say that if you make these in your spare time and are either not protected by product and professional indemnity insurance, or are not deferring responsibility through a disclaimer and warning, then I pray for you that your product holds up. Litigators would make a meal of a broken aftermarket wheel stud in a large personal injury suit.
On your other comment, I quite expect Maserati's wheel nuts to rust - they are made of chrome plated mild steel. We do of course have little idea as to the process they went through (was it triple chrome i.e. copper, nickel, chrome or just straight chrome onto the steel?)
The fact that the original nuts rust is not a safety issue. If people are having them chromed and not de-embrittled, then that is.
Sprogs, I'm not having a go, just giving some subjective opinion. I am quite happy for you to disagree and I won't be upset. If people have all the facts, then they can make their own risk assessment.
As a note to you personally, I would say that if you make these in your spare time and are either not protected by product and professional indemnity insurance, or are not deferring responsibility through a disclaimer and warning, then I pray for you that your product holds up. Litigators would make a meal of a broken aftermarket wheel stud in a large personal injury suit.
On your other comment, I quite expect Maserati's wheel nuts to rust - they are made of chrome plated mild steel. We do of course have little idea as to the process they went through (was it triple chrome i.e. copper, nickel, chrome or just straight chrome onto the steel?)
The fact that the original nuts rust is not a safety issue. If people are having them chromed and not de-embrittled, then that is.
lozcb
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Nothing personal Sniffer ,my referral regarding V bird was in reference to the way in which your post was written ( nothing wrong with it ) in fact it was written in a precise and a very exact manner, but very typical of another technical engineer we had on another forum called V bird extremely knowledgeable and a great guy but used to bore ( offload ) onto everyone with too much specifics , great when its needed and required im not inciting anything just stating the fact of the similarity
regards loz
Andyk
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Ever used or gone under the name of V Bird by anychance
regards loz
V Bird..What ever happened to him....Remember pulling out my street once and he was at a house around the corner....Lived miles away so was a big suprise...
Sniffer, A 10-9 bolt which is more than likely the spec of standard wheel bolts on a maserati has a tensile strength of 1040 n/mm² and a yield strength of 1000 n/mm²
now a stainless bolt made from custom 630 (17-4) has a tensile strength of 1380 n/mm² and a yield strength of 1275 n/mm² this is in H900 heat treat spec which we do , this information is readily available on the net (http://www.beartechalloys.com/type_17_4.htm).
As you can see our bolts are stronger than the originals and don`t rust !, now your point about a rolled thread being stronger than a machined thread i do not really buy as the hubs will no doubt have been tapped at the factory which as you know creates a perfect 60 deg thread form the chances of a rolled thread being a perfect 60 deg form are debatable whilst we can achieve this easily on our cnc machines creating a perfect match of male and female threads meaning more surface area in contact.
rolled threads are done for ease of manufacture and are cheaper to produce.
now a stainless bolt made from custom 630 (17-4) has a tensile strength of 1380 n/mm² and a yield strength of 1275 n/mm² this is in H900 heat treat spec which we do , this information is readily available on the net (http://www.beartechalloys.com/type_17_4.htm).
As you can see our bolts are stronger than the originals and don`t rust !, now your point about a rolled thread being stronger than a machined thread i do not really buy as the hubs will no doubt have been tapped at the factory which as you know creates a perfect 60 deg thread form the chances of a rolled thread being a perfect 60 deg form are debatable whilst we can achieve this easily on our cnc machines creating a perfect match of male and female threads meaning more surface area in contact.
rolled threads are done for ease of manufacture and are cheaper to produce.
lozcb
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lozcb
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Totally agree Sniffer , do you have a nickname Sniffer ,its really erking me and making me think of some hound dragging his snout round the floor everytime i write your name , can i call you jeff or sommet
regards loz
lozcb
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Had a few mails with him over the years Andy , last was that after he got taken to the cleaners and got stiffed for over £110k he got a contract in the M/east to try and clear things
havent heard since
regards loz
Shame VBird isnt, would make for a nail biting saga
regards loz
hahahahaha very good...........
mjheathcote
Centenary Club
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Regarding cut threads and rolled threads, rolled threads are stronger, approximately 25 to 30% stronger, under dynamic loading.
But it all depends on the standards the bolts are made too.
So if the standard the original wheel bolts are made too stipulates the threads must be rolled, to use a cut thread replacement one must assume the material must be 25 to 30% stronger to compensate? As the alternative stainless material appears reading the above to be the case stronger by this amount, all appears to be well, worst case.
I would not worry myself, I am sure there is a large safety factor in the design of wheel bolts holding the wheel in place. Does the veyron have 10 wheel bolts having 1000bhp or what ever it has?!! No.
Cheers,
Mike
But it all depends on the standards the bolts are made too.
So if the standard the original wheel bolts are made too stipulates the threads must be rolled, to use a cut thread replacement one must assume the material must be 25 to 30% stronger to compensate? As the alternative stainless material appears reading the above to be the case stronger by this amount, all appears to be well, worst case.
I would not worry myself, I am sure there is a large safety factor in the design of wheel bolts holding the wheel in place. Does the veyron have 10 wheel bolts having 1000bhp or what ever it has?!! No.
Cheers,
Mike
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davy83
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Having just had my bolt tips chromed by classics and chrome the issue of hydrogen embrittlement is a worry for me. I will find out whether this is a problem they are aware of and have any thoughts on it. However i would throw out one thought here. I suspect the first person to have the bolts chromed was probably ten years ago. I have never come across any one who has experienced a broken wheel bolt. I strongly suspect that the chromed bolts are subject to some Hydrogen effects but are so over specified that it is not enough to make them unsafe. I note in the above article the effect is really only a problem where the material is operating close to its limits. I know in the oil business its a huge issue with down hole pipe which generally only has about 30% safety margin on tensile strength and they have seen fractures, and so on in high H2S wells. I suspect the safety margin on these bolts is probably 200-300%. There was also one remark about why the bolts rust when other manufacturers don't. This I would guess is because it is higher tensile rating than the others. This is a warning to be careful here as I have said before, since it clearly indicates that these are quite high strength bolts. I considered getting replacements before and after looking into it thought better of it, and went down the chroming route. Seems like i should have got used to the rust! I also have had plastic bolt covers made at one time and they actually looked great but were a real pain to get on and off.
lozcb
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For my two penny worth , i have had my 4200 bolts chromed 3 years ago and now there rusty again, not sure on the de-brittling treatment but 20K miles later 3 hair raising track days later, and i do push it a bit , several times up to 165 in the right places of course a few wheels on and off for tyres and me too never cracked or had a bolt break .........maybe ive been lucky................tongue in cheek of course
regards loz
Easyplan66
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I rang classics and chrome today to check and they do not embrittle the bolts before chroming them, should we be worried, I had mine done 18 months ago.
lozcb
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Easyplan66
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point taken..........I don't drive like a lunatic so not too bothered