Hip received small metal bars (6)
I believe the answer is:
ingots
'metal bars' is the definition.
('ingot' can be a synonym of 'metal bar')
'hip received small' is the wordplay.
'hip' becomes 'in' (I've seen this in other clues).
'received' becomes 'got' ('get' can be a synonym of 'receive').
'small' becomes 's' (abbreviation - e.g. clothes size).
'in'+'got'+'s'='INGOTS'
(Other definitions for ingots that I've seen before include "Lumps of metal, say gold" , "Metal bars" , "Brick-shaped blocks of metal" , "Bars, of gold say" .)