Ball bearing Butt hinges
A ball bearing hinge has ball bearings in the knuckle of the hinge to reduce friction and create a permanently lubricated surface area.
This makes opening and closing a door consistently easier, smoother and quieter, plus it helps the door to swing smoothly with less force required.
Most internal doors will require two hinges to function. For doors with added security requirements and/or containing door closers, three hinges will be required to help prevent forced entry.