"Robert Scibienski" wrote in message
...
Whether you are interested in racing cars or not, buy and read
(several times) Carroll Smith's "Engineer to Win". It contains the
best layman's introduction to metals and metallurgy that I have ever
read. When you are done you will know how to heat treat 4130, whether
you need to do so, and if so whether to do it yourself or to have it
done professionally- But you may also decide that you don't need to
use 4130 for your purposes.
Bob S.

Yeah, I was going to point out that 4130 may be a waste of money and time,
and heat treating it may waste more of each. I remember learning about sway
bar design and materials back when I was involved in amateur racing but,
unfortunately, I have a crappy memory. g

However, it would surprise me if a sway bar designed for a high-performance
car would even approach the elastic limit of untreated, cold-rolled steel.
It shouldn't deflect a great deal. Much more likely to need fancy steel and
heat treatment is an ordinary street sedan, in which the bar would be less
stiff, and therefore would need more elasticity.

In any case, the difference in elastic limit between the normalized
condition and the hardened condition is not that great for 4130. It's fairly
strong as it is, and it isn't tremendously strong even when heat treated.

Ed Huntress