Abstract: Pipe cleaners comprising a plurality of short pieces of threads as active elements are formed in machines arranged in pairs. Threads are wound in helices around two rigid wires, which are advanced adjacent and parallel to each other and each belong to a different one of the machines of the pair. The turns of the helices are severed between the wires in such a way that two pieces of thread are formed of each turn. Half of the thread pieces are secured to each wire by approaching one additional wire to each of the firstmentioned wires and twisting the wires pairwise for clamping the thread pieces between the wires of each pair and for forming two pipe cleaner strings, which are subsequently cut into individual pipe cleaners.The common parts of the machines of a pair comprise thread bobbins, thread winding means, thread severing means and means for guiding the thread helices forming wires.