CRANKED SURFACE FIXED AND SECURITY BOLT HINGES

Cranked hinges take the door leaf clear of the door aperture increasing the effective opening width.

Double cranked hinges are for doors that are sometimes called over-rebated or layover doors. These doors are typical on continental Europe and have an additional lip, which “lays over” the external edge of the door frame.

Surface fixed or half surface hinges are usually ‘flat-back’ and designed for face fixing to both the door and frame respectively according to the application required, they are usually applied to metal doors/frames with metal thread screws, bolt-through on the door, and fixed to the door and frame face respectively.

Otherwise they can be used on mineral cored doors or similar constructions where fixings are difficult, to timber or metal frames. Part of the hinge is secured to the door face with bolt-through fixings, and the other part is fixed at right angles onto the inside face of the frame. Metal thread screws are used with metal frames.

Security bolt hinges incorporate an 11 or 12mm security stud. When the door is closed this locates through the frame hinge leaf and into the door frame itself. The security stud feature is designed to prevent the door leaf being removed where the hinge knuckles are located externally, otherwise an assailant could attempt to cut off the hinge knuckles and leaver out the door leaf, the stud prevents this from happening by securing the door leaf within the frame.