Abstract: A stacker for rigid and semi-rigid sheet or pad-like products forming individual stacks thereof of specific count and with the edges of the product in each stack aligned. The stacker comprises at least one pair of multi-thread screws, being mirror images of each other, rotating continuously at the same speed but in opposite directions. Products are continuously fed between the screws of the at least one pair, each product being supported by a set of corresponding threads of both screws. All corresponding sets of threads are so loaded and each product is shifted downwardly by its respective thread set while simultaneously being urged forwardly against a stop to align the front and rear edges thereof. The initial portion of the shaft of each multi-thread screw tapers downwardly and outwardly to align the side edges of the products.