Hinge with two rectangular metal plates with screw holes joined together by a pin or rod.
(or Butt) - A hinge mortised into both the door and frame. Butt Weld - A weld of members butting against each other. Concealed Hinge - A hinge so constructed that no parts are exposed when the door is closed.
Hinge in which both leaves are mortised (cut) into the edge of door and frame.