Work hard fixing rivets (6)
I believe the answer is:
strive
'work hard' is the definition.
'strive' can be an answer for 'work' (thesaurus). I'm unsure of the 'hard' bit.
'fixing rivets' is the wordplay.
'fixing' indicates an anagram.
'rivets' with letters rearranged gives 'STRIVE'.
Can you help me to learn more?
(Other definitions for strive that I've seen before include "Vie, contend" , "Make effort using rivets" , "Make a great effort" , "Make great efforts" , "Venture" .)