Made tough new deal under queen (8)
I believe the answer is:
annealed
'made tough' is the definition.
(annealing is a kind of making tough)
'new deal under queen' is the wordplay.
'new' indicates anagramming the letters.
'under' means one lot of letters go next to another.
'queen' becomes 'anne' (Queen Anne, 18th-century queen).
'deal' with letters rearranged gives 'aled'.
'aled' after 'anne' is 'ANNEALED'.
(Other definitions for annealed that I've seen before include "Like heat-treated metal" , "made tougher" , "Strengthened" .)