Copper fan, perhaps, one used to screw in place? (9,3)
I believe the answer is:
butterfly nut
'one used to screw in place?' is the definition.
(nut used to secure something)
'copper fan' is the wordplay.
'copper' becomes 'butterfly' (copper is a type of butterfly).
'fan' becomes 'nut' (both can mean an enthusiast).
'butterfly'+'nut'='BUTTERFLY NUT'
'perhaps' acts as a link.
(Other definitions for butterfly nut that I've seen before include "One screwed up" , "Lepidopterist" , "Two-winged fastener" , "helping to make connections?" .)