Sword metal (5)
I believe the answer is:
steel
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">sword metal</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for steel that I've seen before include "Form of iron" , "Hard iron alloy" , "The staying power" , "Strength, determination" , "Strong metal" .)