Abstract: A demolding mechanism for demolding a molded article with internal thread is provided. The demolding mechanism includes an outer sleeve and a core. The sleeve includes a number of spring legs and a body. Each spring leg has an external thread. The core includes an end portion and a cylindrical shank. The end portion includes a central portion and a number of evenly spaced ribs. The diameter of the core is smaller than that of the sleeve. The sleeve is slidable along the core. When the spring legs move away and disengage from the ribs, the spring legs are configured to deflect inwardly, thereby enabling the external thread thereof to disengage from the inner thread of the molded article.