All hollow metal doors are manufactured as two pans with an edge seam. Some are made with an offset concealed edge seam, which is 1/4″ from the push side of the door. This is suitable for the commonly specified mortise locks and mortise exit devices that have 1-1/4″ faceplates, and are automatically centered when abutted to the 1/4″ edge seam. (1/4″ 1-1/4″ 1/4″ = 1-3/4″).