xb-60, you may have taught me something. I was thinking mild steel such as 1020 contained no more than 0.2% carbon? Being the second two digits represents the carbon quantity. Same in all steels a high carbon of 1040 equaling no more than 0.4%?

Ralphy

You have never seen the item, don't know how it works, and never used it, but you are going to sit here and argue its merits and what it will and won't do.

Yeah....discussion is over on this item. You can't argue with ignorance.

Joyridin, I don't have to use this to research it and its uses, just like I don't have to use crack to understand it is a bad drug. I have performed the required research and have verified it does not meet the Mil Spec criteria for determining material composition and is therefore not usable for my applications. Check it out for yourself and tell me I am wrong in this statement. I do this sort of thing all day long, yawn...

I wish you the best in your endeavours and, as said before, I am certain you are using this device within its intended parameters and hope it provides you with many years of profitable service.

Kryptonite; off limits for me personally.

[ame=http://www.youtube.com/watch?v=wcW_Ygs6hm0]Major Kong Rides the Bomb - YouTube[/ame]

Ralphy

That's where the disconnect is, Mil Spec criteria is NA for this application of determining metal composition ... we don't shoot '65 cobras into space. Obviously a portable metal spectrometer has a "market" or they wouldn't make it, and perfectly suitable for the purposes discussed here (probably more accurate than the spec sheet coming from the raw stock metal supplier in '65). For a guy that's been in the aerospace biz for 24 years, you ought to know ground support equipment comes from suppliers typically following best commercial practices with an acceptable QMS, Mil Spec requirements have no place here.

Ralphy,
My figures were for CA2S-E (cold rolled, formable) http://www.bluescopesteel.com.au/files/CA2S-E.pdf
which is similar to 1010, and has a max carbon content of 0.10%
You're correct that 1020 has a maximum carbon content of 0.20%
Cheers,
Glen

Al and others: I get the point about this application might not need to be particularly accurate. You may be correct. I'll top that by suggesting that AC would have been unlikely to specify anything other than 'mild steel' and probably got materials over the years from various suppliers , which would make determining authenticity by comparing to sibling materials very dicey, even with the highest accuracy equipment and techniques.

Also, since you brought it up, most GSE is not even allowed to be built to industry practices due to the sensitivity of lifting, handling, interfacing, or pressurizing one-of-a-kind, high-value hardware. the downside of a COTS GSE component failure is just too catastrophic in terms of human and financial loss (think of dropping a large rocket motor). There are some exceptions to this of course, but most GSE just defaults to being Mil Spec compliant. You have no idea what it takes to get NASA (and customers in general), the Ranges (who let us integrate on their proerty and let us fly out), the FAA(who controls the airspace), the DOT (who allows us to ship over the nations hiways), DCMA (who lets me handle and test ordnance), the DOD, and a myriad of others who poke their noses in my business to all agree that things are kosher. Most times it is just best to be able to point to a Mil Spec in order to stop the incessant do-loops that cost even more to navigate than complying with Mil Specs. Commercial Programs may be a target of opportunity for industry common practices and are assessed on a case-by-case basis, but that doesn't fly at all on DOD Programs, even for GSE.

I never saw a material..... well I never cut a material with that low of carbon. We used to get a material called leadloy. You could fly thru the stuff. I believe leaded metals are gone. That must be nice for forming.

Added:
Maybe it's still available, it was 12L14 and called ledloy not leadloy.

Ralphy

Ledloy is still a low carbon steel with carbon content at 0.15%, but it has 0.15 to 0.35% lead content which makes it a very easy machining and ductile steel
Cheers,
Glen

I still have a lot of customers machining 12L14. I still have one machining 41L40. I have no idea where they actually buy the 41L40.

portable x-ray analyzers can be had for much less that $20k. If you have a sample of the tubing, grind an area down to bare metal, clean it, then take it to a scrap yard that buys/recycles metal... they should have one. (they can also probably be rented, tho it would be pricey) Altho I don't know that I'd rely upon the results with respect to carbon content (which is the primary alloying element in a plain carbon steel). Ideally, carbon content is best analyzed via combustion. A 1020 plain carbon steel is, in general, pretty similar to an ASTM A36 steel... which would have a minimum yield strength of 36 ksi, and an ultimate tensile strength of 58-80 ksi. The requirements for a plain carbon steel are so loosely defined that a beer can would meet it. Having tensiles pulled would be more involved... and more costly... and definitely destructive. An alternative would be hardness testing with a portable, rebound-type hardness tester. The hardness-to-tensile strength correlation is pretty good for carbon steels. A commercial testing lab could probably get you chemistry & tensile/hardness for $300 or so.

Uuups I opened the Pandora's box.

Plase no more fighting about devices and stuff - I was just interested if the steel from the Frame -. as being the "heart" of a car could be evaluated as genuine if we test this material.
I do still believe it would be an interesting add-on to proof the originality of a car. (Besides other indications of course) But with all these engines exhanged in period and later, all the re-worked interiors, all the custom made parts, all the interchangabel components and finally all the repaired/rebuilt bodies - there is not really a lot which is really genuine. Right?
So how to do figure this out? There must be a reason, otherwise folks like Ferrari Classiche and Mercedes Benz Historic Centre wouldn't do it as well?!

So what is the magical formula of genuine Cobra-frame steel???

What about doing a DNA test on the steel chassis?
Cheers,
Glen

And we have an early contender for 2014 forum quote of the year!

GSE is allowed to be built to industry/best commercial practices as long as the right checks & balances are there. You kind of forgot about the proof load cert with RFU tag (for lift, MEOP etc) but that's ok. You also forgot about the approved suppliers list where current ISO 9001 or AS9100 registration is a DoD requirement, but that's ok too. Bottom line, DoD can't move to COTS fast enough to get under the ISO/AS9100 umbrella and ditch outdated Mil Specs altogether.

not fighting... just trying to help.

call Shelby American... they may have an idea... tho who knows how many suppliers they bought their steel from over the years.

which brings me to a question... did the "original" Shelby 427 Cobras use a modified AC chassis, or was it a completely new chassis mfd by Shelby?

... but there may not BE a magical formula...

steels made today CAN BE much cleaner than those of 50 years ago, and most likely have more consistent/reproducible mechanical & microstructural properties... so as far as formula/composition... you could probably argue that the crappier it is, the older/more authentic it probably is. (tough to prove tho) Domestically made steel was, for many years, considered superior to that produced overseas- tho I think that has finally changed. Most of the major steel mills have been replaced by recycling/mini-mills and/or specialty mills. Most of the undesirable elements/contamination can be removed... some do it better than others. The "cleanliness" of the steel can be analyzed via several techniques... it just takes time... and money.

Al,

Glad you think know my business so well, hahaha. You sound like a supplier/salesman.

It was a completely new chassis manufactured by AC Cars.
We are talking about the early/mid 60's cars here aren't we?

Yes we talk about the original MKI & MKII as well as about 427s.