SS FLUSH DOOR HINGES are the best option for Main Doors and Bathroom Doors, The Two Ball bearings within the pivot make them good for heavy Doors as they can hold as much weight as butt hinges and Ball-bearing hinges. SS FLUSH DOOR HINGES are very easy to fit as they can be fastened directly to the door frame and do not require more effort. The smaller side on a flush hinge fit on the narrowest side - whether it is the door or the cabinets depends if they're overlay or inset and so determines whether the cranked knuckle faces 'in or out.