National Hardware N236-012 Adjustable Steel Spring Hinge, Satin Chrome, 4-1/2"National Hardware 2060R Adjustable Spring Hinge is ideal for use in corridors, entrances and stairways. Automatically closes door an alternative to overhead mounted door closers. Patented ratchet adjustment eliminates need for adjustment locking pin. Meets NFPA8 standard for 3 hour fire rated doors minimum 2 spring hinges per door required. UL listed for doors up to 4' x 8' weighing up to 180 lbs. Conforms to ANSI BHMA standard A156. 17, Grade 1.