Hinges shall be manufactured of three interlocking components, two hinge leaves and one cover channel. The door leaf and jamb leaf shall be geared together for the entire length of the hinge, and joined by a cover channel. The pinless assembly of three interlocking extrusions shall be applied to the full height of the door and frame without mortising. All unexposed working metal surfaces shall be coated with TFE dry lubricant. Hinges of greater length will have proportionately greater numbers of bearings.
Beatings are to be completely concealed in the cover channel.
Hinge cover channel is to be monolithic in appearance and withstand 7000 foot pounds of pull apart pressure. Hinges with visible knuckle separations are not acceptable. Six screw holes shall be concentrated at each end of the hinge and additional screws are proportionately spaced along the full length of the hinge. All hinges shall carry Underwriters Laboratory Inc. certification, up to and including all 90 minute applications for wood doors, as well as 3 hour applications for all fire rated hollow metal doors. Fully Concealed type hinges shall not require any special pins or studs lbr any type of fire ratings up to and including 90 minute hollow metal door and hollow metal frame applications.