Smooth piece in gritty construction (10)
I believe the answer is:
sandcastle
'gritty construction' is the definition.
(castle made of sand or grit)
'smooth piece' is the wordplay.
'smooth' becomes 'sand' (sanding is a kind of smoothing).
'piece' becomes 'castle' (castle is a kind of chess piece).
'sand'+'castle'='SANDCASTLE'
'in' acts as a link.
(Other definitions for sandcastle that I've seen before include "Fortress constructed on the beach" , "one that goes with the flow?" , "Model on a beach" .)