I know its something that a magnet will hold, but is it mostly iron or what?

thanks!

 

spring steel

 

Vanadium Chrome Silicon Steel

 

 

Thanks Everyone!

 

Actually you are more correct than you realize. All steel, even valve spring steel only has a few % of the alloying elements like Chromium, Vanadium, Carbon, Silicon, Sulphur. etc. The balance is iron! Of course it's not anything like Cast iron you'll find in blocks, some heads, etc.

As important as the alloy is the purity of the steel. Any impurities like "dirt" that get trapped inside the wire cause stress risers which can lead to failure with more time on the engine. OEM springs and lifts are chosen to not stress the springs as highly as we do with aftermarker cams.