a stacking device for stacking headed tubular fasteners . the device comprises air blowing means which accelerates an end fastener in a guide relative to the remaining fasteners in the guide thereby ensuring that each fastener leaves the guide separately without jamming to fall into a stacking passage in which the fasteners form a column one - above - the - other . the stacking device is utilized for stacking rivets in a rivet packaging machine which assembles a column of rivets on a sleeve made of resilient plastics material for later transfer to the mandrel of a pull - through blind riveting tool .