Obliterates keys to steel production (7)
I believe the answer is:
deletes
'obliterates' is the definition.
(to delete is to obliterate or remove)
'keys to steel production' is the wordplay.
'keys' becomes 'de' (I've seen this in other clues).
'to' is a charade indicator (letters next to each other).
'production' indicates an anagram.
'steel' is an anagram of 'letes'.
'de'+'letes'='DELETES'
(Other definitions for deletes that I've seen before include "Crosses out" , "Erases" .)