In this article, yarn was spun by processing sewing threads and adding fibers to cotton fiber, and in the laboratory of the Department of Spinning
Technology, up to 400, 500 and 600 br/m were added to the yarn during the spinning process. 4 different options were obtained for testing: 70% cotton fiber + 30% cotton return, 80% cotton fiber + 20% cotton return, 65% cotton fiber + 35% cotton return and 90% cotton fiber + 10% cotton . samples of threads from fibrous threads, their single-period elongation deformation was detected in the laboratory "CentexUz" of the Tashkent Institute of Textile and Light Industry.