Abstract: Mechanical self-centering device to center a moving web of thin sheetlike material such as paper, plastic, metal or the like to prevent the web from drifting from side to side as it moves from one mechanical device, such as an unwind stand, to another mechanical device, such as a printing press, coating apparatus, a web splicer, a machine to fabricate finished products from the web such as a cup-making machine, or the like. The self-centering device comprises a roller extending transversely across the path of travel of the web and adapted to rotatingly contact the moving web on one side thereof. The roller is rotatingly mounted in a bracket which is free to pivot about an axis which is spaced from, and which extends generally parallel to, the path of travel of the web.