This standard specifies the technical requirements, test methods, inspection rules, marking, packaging, transportation and storage requirements for nylon elastic yarn products. This standard is applicable to nylon 6 and nylon 66 with a main line density of 16 to 112 dtex (single line density of 2 to 5 dtex) and its ply yarns, with glossy, semi-matt, natural color, and circular cross-sections. Quality identification and acceptance of elastic yarn.