Short piece of brass tubing (4)
I believe the answer is:
stub
'short piece' is the definition.
'stub' can be an answer for 'piece' (stub is a kind of piece). I'm not certain of the 'short' bit.
'of brass tubing' is the wordplay.
'of' indicates the answer is hidden within the clue.
'STUB' can be found hidden inside 'brass tubing'.
Can you help me to learn more?
(Other definitions for stub that I've seen before include "Pencil or cigarette end" , "evidence of smoking, for example" , "Stump, of a cigarette say" , "Butt of pencil or cigarette" , "Tooth remnant" .)