Put a metal (steel) coat hanger on an anvil and tap it with a hammer. Flattens? If it does, it is "malleable" and then steel is malleable. Be careful with your definitions.
I'm sure you would say the same thing if I used the word DUCTILE or even the term PLASTIC DEFORMATION.
I could say use a magnet but then that would be negated by some types of stainless steel.
So where do you want to draw the line?
Back to the subject, If you get plastic covered metal; you have steel for sure as the manufacturers of non lead wheel weights are not currently covering zinc with plastic.
Pure Zinc has a melting point of just under 790 degrees. It goes into the 8's depending on the impurities or alloying materials.