A spring hinge is a type of hinge that incorporates a spring mechanism, allowing it to automatically return to a closed position after being opened. This feature is commonly used in doors, gates, and cabinets, providing convenience and ensuring that the door remains closed when not in use. The design of a spring hinge typically includes two plates connected by a pin, with a coiled spring that provides the tension needed for the automatic closing action. Spring hinges are often found in commercial settings, such as restaurants and offices, where frequent door use is common.