Ball bearing hinges have always been very popular for their smooth operation, durability, long lasting design and ability to carry heavier loads than other hinges. They carry a CE mark and are Certifire tested. BS EN 1935 rated. This substantial premium hinge carries a 25 year mechanical guarantee. Suitable for standard internal residential doors a pair of hinges is adequate; however fitting 3 hinges per door has its advantages: it will look aesthetically pleasing and from a practical viewpoint it helps spread the load evenly and will help to overcome twisting or warping. Suitable for all domestic, commercial and industrial use.