Steel component (4)
I believe the answer is:
iron
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">steel component</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for iron that I've seen before include "Club; element" , "Very robust" , "A magnet attracts it" , "Ferrous metal" , "Flatten; element" .)