National 1/4 In. Radius Spring Door Hinge
Catalog model No. V521 series. Cold-rolled steel. Designed for hanging self-closing doors in basements, stairways, garages, and entrances. Can be used in residential, commercial, and apartment buildings. Hinge is UL approved for fire doors. Closing speed is adjustable. Fits standard hinge cutout. 1/4″ radius, round corner automatic door-closing spring hinge.