Grade 7 Ball Bearing Hinge (Max Load 40kg). They have a CE mark and are Fire door rated. BS EN 1935 rated. Ball bearing hinges have always been very popular for their smooth operation, durability, long lasting design and ability to carry heavier loads than washered hinges. 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. This can sometimes happen to doors over a period of time where heat and moisture are a factor. Comes with a 10 year mechanical guarantee. Suitable for domestic use.