carbon steel

from WordNet (r) 3.0 (2006)

carbon steel
    n 1: steel whose characteristics are determined by the amount of
         carbon it contains

from The Collaborative International Dictionary of English v.0.48

Carbon steel \Carbon steel\
   Steel deriving its qualities from carbon chiefly, without the
   presence of other alloying elements; -- opposed to {alloy
   steel}.
   [Webster 1913 Suppl.]