I found this interesting thread when I Googled "Supertanium" A former SCCA guy
I know (69 Formula B National Champion) used to ONLYuse these in his shop and
they were more than a grade 8 and had a thick head and a nice appearance.
It is a marketing name and I am not sure which came first: Supertanium or Mark
Donahue's "unobtanium" (what a great word).
Anyway, this thread is an interesting lesson for those that think more is
always better. Having done the QC inspection in a metallugical lab for my fair
share of parts, hydrogen embrittlement was a big concern especially for
stainless steel. We were concerned about the speed of the quench through a
specific temperature range that would trap hydrogen in between the grain
boudaries.The issues with plated parts, which I never dealt with, are similar
in the end result (failure) but plating can trap hydrogen due to the plating
chemicals and that needs to be baked out properly. Harder materials are more
susceptible and these engineers have an interesting thread for those inclined
to the technical details behind what makes the appropriate fastener for the
job. The upshot of this is be very careful when choosing and selecting
fasteners, especially for suspension parts. If you dig into this you will find
a reference to failed Humvee suspension bolts and that should not be easy with
all the
certifications that are required for mil spec bolts but it still happens.
Some flunky jerks another Rockwell point on the inspection so a borderline lot
"meets spec" and someone could die. You never know.
http://www.eng-tips.com/viewthread.cfm?qid=95071&page=6
Bob Melusky
---------------------------------
Yahoo! FareChase - Search multiple travel sites in one click.
|