6 in. Prime Coat Double Acting Spring Hinge with Steel Base (Set of 2)Keep commercial doors safe with Trans Atlantic Co. 6 in. x 6 in. double acting spring hinges. Designed for automatic doors to securely self close, this hinge is great for doors that open to each side and automatically return to the center. Engineered for doors that are 1 1 4 in. to 1 3 4 in. thick. Double acting spring hinge without hanging strip Minimum door width: 2 ft. 4 in. Maximum door width: 2 ft. 8 in. Full mortise type For 1 1 4 in. to 1 3 4