A capping head comprising a support adapted to be associated with means arranged within a capper comprising at least two identical working units, which are associated with the support and are motorized in the same direction, each working unit comprising a shaft provided with motor drive means, which is connected, with the interposition of a torque-limited coupling, to a transverse arm adapted to support a rotating roller, both rollers are designed to come into contact with a cap to be screwed onto a container.