Metal block (5)
I believe the answer is:
ingot
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">metal block</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 ingot that I've seen before include "Piece of precious metal" , "Bar, brick of metal" , "Mass of unwrought gold, for instance" , "Metal casting" , "Form of gold or silver" .)