National Hardware 3-1/2" x 1/4" Radius Brass Spring Door Hinge is crafted from cold-rolled steel, making it a durable and reliable choice for hanging self-closing doors. This hinge is i for use in basements, stairways, garages, and entranceways, and it suits residential, commercial, and apartment buildings alike. It is UL for fire doors, ensuring safety and compliance. The closing speed is adjustable to meet your specific needs, and it fits standard hinge cutouts with a 1/4" radius, round corner design. This automatic door-closing spring hinge combines functionality and quality for everyday use. Model Number: N185-199