For the other end of the spectrum, try comp.arch.fpga
There is a bit of clash between the Xilinx and Altera personnel, but
it's quite active, high on technical content, and very low on noise.
The down side is that nobody there wants to talk rockets. Not much fun
Are you "legal" with the DOT? you have always maintained that you were
legal. That's BS
you claimed you were legal, even after the DOT fined you.
Are you "legal" now? What's the name of your ATF agent?
Who is your current DOT contact?
The two are simply application and quality designations for given alloys.
The terms don't tell you the chemistry or mechanical properties, they only
suggest quality and condition needed for a typical application. This is why
I personally hate using these types of terms. I want to know what the
chemistry and heat treat condition is, not the type of steel.
Springs need to have very high yield strengths. Chemistries and heat
treating techniques are employed to achieve the needed properties. Thus,
steel alloys used for springs have a significant amount of elements that
increase hardenability such as carbon, silicon and manganese. The
disadvantage is that they are brittle. (Ever seen a broken spring?)
Music wire needs very high tensile strengths and a small amount of corrosion
resistance. Thus, steel alloys used for music wire have elements like
chromium and nickel. The quality of the steel also extremely important
because it is very demanding to draw a steel alloy to the sizes used for
musical instruments. The steel alloy needs to be very clean, having
absolutely no inclusions or other defects from melting/pouring/casting at
the steel mill.
Both of the materials need to have resistance to fatigue. Neither one is
"better" for launch rods. Neither one is "stiffer".