Abstract: A hinge member for a blow-molded article includes at least two hinge arms with axial holes defined therein and a hinge pin extended therethrough. The hinges arms include upper and lower ones provided on the two parts of the article respectively. At least two openings are defined in the wall of each hinge arm and parallel to a horizontal plane at which the axis of the axial hole is located. At least one opening is positioned at each side of the horizontal plane. The length and width of the openings are arranged such that each opening corresponds to a particular section of the axial hole. The axial hole can be formed by providing corresponding bulges in the mold without removing a core pin, thereby simplifying molding process and increasing yield rate. The present disclosure also provides a blow-molded article having the hinge member and a mold for forming the article.