Friends about to produce a hit (4)
I believe the answer is:
slap
'a hit' is the definition.
(I've seen this before)
'friends about' is the wordplay.
'friends' becomes 'pals' (pal is a kind of friend).
'about' says the letters should be written in reverse.
'pals' backwards is 'SLAP'.
'to produce' acts as a link.
(Other definitions for slap that I've seen before include "Make-up (slang)" , "Hit with the palm" , "Cuff" , "Strike action" , "Sharp smack" .)