The invention concerns a cap (1) comprising as assembly consisting of:
a) a plastic insert (2) comprising a head (3) with closure means
(31, 32) and a threaded skirt (4), and b) a metal wall. The invention
is characterised in that: 1) said metal wall (5) covers all or part of the
outer surface of said insert (2) and includes at least a metal skirt (51)
for receiving said skirt (4) of said insert (2); said metal skirt
(51) includes an edge (510) crimped to said insert (2) so
as to assemble together said metal wall (5) and said insert (2);
3) said cap comprises means designed to provide weight and/or volume to the part
of said cap located above said sealing closure means (31, 32).
