The word catenary is derived from Latin word for ‘chain’. Nowadays, it is known as the shape of chain carrying nothing other by its weight suspended by its ends and acted on by gravity. The shape itself is easily encountered in the simplest forms of things of our surroundings such as spider’s web and suspended bridge. Commonly adapted to kiln, the catenary shape is adapted to doorway to achieve ideal shape for freestanding arch of abiding extent. All of the catenary door is an enginereed door which is exercised based on the efficiency of ergonomy, height of the people, ease to open the door, adjusted for the owner’s dimension, the minimum size of opening, the limitation of hinge and combination of steel.