5402.31 - Of nylon or other polyamides, measuring per single yarn not more than 500 decitex:

This HTS category, 5402.31, specifically covers textured synthetic filament yarn made from nylon or other polyamides. A key defining characteristic is that each individual yarn strand within this classification measures no more than 500 decitex. These yarns are not intended for retail sale and fall under the broader scope of synthetic filament yarns.

It is crucial to distinguish 5402.31 from its siblings based on two primary factors: the decitex measurement of the single yarn and the material composition. For instance, HTS code 5402.32, while also covering nylon or polyamide textured yarns, applies when the individual yarn measures *more than* 500 decitex. Other siblings, such as 5402.33 and 5402.34, differentiate based on the specific synthetic material, covering polyester and polypropylene textured yarns, respectively.

Within the 5402.31 category, further subdivisions exist to account for the construction of the yarn. Subcategory 5402.31.30.00 pertains to single yarns, meaning the filament has not been twisted with other filaments. In contrast, 5402.31.60.00 encompasses multiple (folded) or cabled yarns, where two or more single yarns have been combined and twisted together. This distinction is important for accurate tariff application, reflecting different manufacturing processes and potential end-use characteristics.