Element used in steels (9)
I believe the answer is:
manganese
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">element used in steels</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for manganese that I've seen before include "steel component" , "Metallic element, Mn" , "Metal used in some steels" , "Metallic element used in steels" , "Hard grey metal, Mn" .)