National Hardware 4" Oil Rubbed Bronze 1/4" Radius Spring Door Hinge is crafted from cold-rolled steel and designed specifically for hanging self-closing doors in areas such as basements, stairways, garages, and entrances. This versatile hinge is suitable for use in residential, commercial, and apartment buildings, ing reliable performance. It features a 1/4" radius round corner and is UL for fire doors, ensuring safety and compliance. The closing speed of the hinge is adjustable, and it fits standard hinge cutouts, making installation straightforward and convenient. Model Number: N350-850