Alan Scott, the Green Lantern of Earth-Two, tracked his Metal Men of Jupiter to mines wherein the creatures were consuming and adopting the attributes of Magnesium. While Lantern had mastery over most metals, this particular metal seemed to cause him some difficulty defeating, at least initially. Thankfully, with a bit of will power, the tide would turn.
With his power ring doubling as a blow torch, he melted his foes down to size before flying off to aid his pals.
Lead of the Metal Men was that Earth-One team's first line of defense, literally, as his superior mass provided a capable if clumsy shield that more often then not saved Doc Magnus from having to construct more Metal Men replicas after the last versions were destroyed by foes.