Metal mix (5)
I believe the answer is:
alloy
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">metal mix</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 alloy that I've seen before include "Metals fused together" , "Amalgam" , "Mixture of two or more metals" , "A mix of two or more metals" , "temper" .)