11.9 Bolt Grade

Revega, Tim

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Apr 6, 2000, 3:00:00 AM4/6/00

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I received two bolts which were part a heavy hauler truck rear axle failure.
I would like to confirm the bolts meet there specified properties however am
having some difficulty identifying the bolting specification. One of the
bolts is stamped 10.9 which I found is manufactured to ASTM F568. The other
bolt is stamped 11.9 however is not listed in this specification (I believe
I have the latest revision - 1995).

I have contacted the vendor however they did not want to comment. Any help
on finding the bolting specification would be appreciated.

Keith

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Apr 6, 2000, 3:00:00 AM4/6/00

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Are you sure it was manufactured to F568? That spec was ASTM's answer
to the SAE J429 (Society of Automotive Engineers) specification. You
might want to check it out because it covers automotive bolt grades up
to 12.9.

Good luck.

On 6 Apr 2000 12:06:00 GMT, "Revega, Tim" <reveg...@syncrude.com>
wrote:

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Dillagi

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Apr 6, 2000, 3:00:00 AM4/6/00

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11.9/ 12.9 grades are basically metric grade materials. It would help if you
see DIN standards. They were the originators of these specs. And it might be
of interest to note that , first digit indicates the approx ultimate
strength in n/mm2 (12.9 - has 120 n/mm2, if you multiply the first no. with
second no. you will get the approx yield strength - 12x9- 108 n/mm2). Hope
this will be of some help.
Best of Luck.

Hephaestus

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Apr 7, 2000, 3:00:00 AM4/7/00

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Hi Tim,

the numbers are a strength designation, the digits to the left of the
decimal point indicate minimum tensile strength in kgf.mm-2 (started life
as a DIN spec), and the number on the right gives the yield to tensile
ratio.

Thus, your fasteners will have a tensile strength of 10 kgf.mm-2 and
11kgf.mm-2 respectively, with a yield strength not less than 90 % of
tensile.

i think you'll find that grade 11 is non-standard, normal high tensile
grades are 8, 10, 12 and sometimes 14.

regards

tim

Revega, Tim <reveg...@syncrude.com> wrote in article
<8chuj8$ms$1...@campus3.mtu.edu>...

Daniel Kohl

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Apr 9, 2000, 3:00:00 AM4/9/00

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You are close to the right answer. But imagine the size of the bolts
that would be needed to hold something more powerful ;-).
Multiply all your results by 10 and you have the right values. Means:

An 11.9 bolt is able to hold 1100 N/mm^2 (at least), while the
yielding strength is 11 * 9 * 10 = 990 N/mm^2.
This fabric is bend by 9 % by the time it breaks.

Best Regards
Daniel Kohl

Dillagi

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Apr 10, 2000, 3:00:00 AM4/10/00

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Forgive me, Kohl was correct. What is it, I think I was bleary eyed, when I
keyed in that.
Beg your pardon.

Hephaestus

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Apr 10, 2000, 3:00:00 AM4/10/00

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Careful here. The original bolt spec was in kg.mm-2, lots of folks simply
read it as MPa, but the conversion isn't a straight 10, but 9.80665. Thus
grade 10 isn't 1000 MPa, but 980.665MPa. Most times, this doesn't matter.
if it does, it'll bite you.

tim

Daniel Kohl <danie...@gmx.de> wrote in article
<38f2e1a7...@news.cs.tu-berlin.de>...

Quentin Smith

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Apr 20, 2021, 6:32:05 PM4/20/21

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11.9 grade is found in ASTM F-2882/F-2882M.