Abstract: Machine for automatically forming hard folders for bindery, comprising:--means for individually feeding the folder's two mirror-sections and central backbone matched to the respective lining sheet--means for pressing each paired elements thus fed;--means for horizontally moving each pair thus pressed;--means for beating the first and then the second trasverse rim projecting from the lining sheet onto the trasverse edge of the corresponding cardboard mirror-section;--means for moving backwards the angular portion of each trasverse rim being beaten and protruding out of the corresponding cardboard mirror-section;--means for beating the protruding longitudinal rims of the lining sheet onto the corresponding sides of the cardboard mirror-sections and backbone;--means for pressing the said pair with the thus beaten rims of the lining sheet. (FIG. 1).