5401 - Sewing thread of man-made filaments, whether or not put up for retail sale:

HTS Code 5401 encompasses sewing thread specifically manufactured from man-made filaments, regardless of whether it is presented for retail sale. This classification includes threads made from both synthetic and artificial filaments, designed for use in stitching and sewing applications. The key distinguishing factor is the material composition – these threads are derived from manufactured polymers, not natural fibers like cotton or silk.

Within the broader HTS structure, Chapter 54, to which 5401 belongs, is dedicated to man-made filaments. This positions sewing thread made from such materials alongside raw filament yarns and other products where the primary characteristic is the man-made filament itself. Therefore, goods classified under 5401 are distinct from natural fiber sewing threads or sewing thread made from other materials.

Subdivisions within HTS code 5401 differentiate based on the specific type of man-made filament used. The two primary subcategories are for threads made of "synthetic filaments" and those made of "artificial filaments." This distinction is critical for customs purposes as it reflects the different manufacturing processes and chemical origins of these filament types, influencing their properties and market applications.