The present invention relates to a method and a device for manufacturing plate part blanks for a heat exchanger. A sheet material (2) in the form of continuous sheeting is worked between two rolls (5, 6) with opposite surface patterns (7, 7′, 8) to form profiled plate part blanks (3, 3′,3″) into the sheet material (2) so that the rolls (5, 6) are synchronized to rotate at substantially same rate by controlling the rotation of them in relation to each other with common synchronization gear (9), which gear is coupled to the rolls (5, 6) by means of shafts (10, 11) with disk pack or gear couplings.