Ball bearing hinges, also known as ball race hinges, have tiny ball bearings hidden within the hinge knuckle that can reduce friction and can help solve the issue of a squeaking door. They are perfect for heavier internal doors and are available in a variety of sizes and finishes. Ball bearing hinges are usually more durable (knuckles can rub against each other and bearings prevent this), perform higher and are not as noisy in operation as standard hinges. They also provide a smoother open and close operation compared to standard butt hinges. The bearing on a hinge typically refers to the weight load that a hinge can handle. Ball bearing hinges often can accommodate heavier and high traffic doors.