Abstract: A rotatable neck ring assembly for use primarily in an automatic blow molding machine includes an annular bushing and a concentrically arranged series of pivotally mounted foot members which in their closed position, cooperate with the bushing to grip the rim of a parison and hold it securely during the molding process. These pivoted foot members, which are spring biased to a closed position, are kept into firm engagement with the bushing by the upwardly moving parison mold. A first cam surface on the outer surface of the foot members cooperates with a corresponding surface on a concentrically surrounding sleeve to hold the foot members tightly against the bushing to grip the rim of the parison and hold it securely during the molding process. The cooperating cam surfaces on the foot members and the surrounding sleeve create a hoop tension in the bushing which must be overcome to pivot the foot members to open position at completion of the molding process.