One toughening up an item for the pew, we hear (8)
I believe the answer is:
annealer
'one toughening up' is the definition.
(to anneal is to toughen up glass)
I can't explain the remainder of the clue.
(Other definitions for annealer that I've seen before include "One heat-treating glass or metal" , "My job is toughening" , "One treating metals with heat to release stresses" .)