Sculptor putting extreme pressure on mug (7)
I believe the answer is:
epstein
'sculptor' is the definition.
(Jacob Epstein)
'extreme pressure on mug' is the wordplay.
'extreme pressure' becomes 'ep' (engineering term).
'on' is a charade indicator (letters next to each other).
'mug' becomes 'stein' (stein is a kind of mug).
'ep'+'stein'='EPSTEIN'
'putting' acts as a link.
(Other definitions for epstein that I've seen before include "produced a few bronzes" , "British sculptor, d. 1959 - Beatles manager, d. 1967" , "Brian --, Beatles manager" , "old artist" , "pop group's manager" .)