A butt hinge is a type of hinge that is commonly used on doors and lids. It consists of two rectangular leaves that are joined together by a pin. The leaves are mortised into the door and frame, allowing the two to butt up to each other. There are three different types of butt hinges: plain, ball bearing, and spring-loaded. Plain butt hinges are generally used for lightweight interior doors, while ball bearing hinges are ideal for heavy entryway doors or those that sustain frequent use. Spring-loaded butt hinges are used to assure a door closes behind you. A butt hinge is a compact, strong, and dependable hinge solution appropriate for nearly every sort of door installation, including cabinet doors, entrance doors, and exterior gates.