Youngsters writing about wrought iron (6)
I believe the answer is:
minors
'youngsters' is the definition.
('minor' can be a synonym of 'youngster')
'writing about wrought iron' is the wordplay.
'writing' becomes 'ms' (abbreviation for manuscript).
'about' means one lot of letters goes inside another.
'wrought' indicates an anagram (wrought means beaten into a new shape).
'iron' is an anagram of 'inor'.
'ms' going around 'inor' is 'MINORS'.
(Other definitions for minors that I've seen before include "They're under-age" , "could be little ones" , "They're too young to vote" , "They are legally under-age" , "Young people" .)