Silver or steel (5)
I believe the answer is:
metal
I believe this clue is a double definition.
'silver' is the first definition.
(I've seen this in another clue)
'steel' is the second definition.
(steel is a metal)
(Other definitions for metal that I've seen before include "Lead or iron, perhaps" , "tin, perhaps" , "Element eg for road or rail" , "Substance as gold, iron" , "Copper or gold, say" .)