Hahnium used by unknown creators for punches (9)
I believe the answer is:
haymakers
'for punches' is the definition.
(haymaker is a kind of punch)
'hahnium used by unknown creators' is the wordplay.
'hahnium' becomes 'ha' (I am not sure about this - if you are sure you should believe this answer much more).
'used by' is a charade indicator (letters next to each other).
'unknown' becomes 'y' (algebra).
'creators' becomes 'makers' (maker is a kind of creator).
'ha'+'y'+'makers'='HAYMAKERS'
Can you help me to learn more?
(Other definitions for haymakers that I've seen before include "Hard blows" , "some in agriculture" , "those taking advantage of sunshine?" .)