6203.31.50 - Of worsted wool fabric, made of wool yarn having an average fiber diameter of 18.5 microns or less

This HTS category, 6203.31.50, specifically covers suit-type jackets and blazers for men and boys that are constructed from worsted wool fabric. A critical defining characteristic for inclusion in this classification is that the wool yarn used in the fabric must have an average fiber diameter of 18.5 microns or less, indicating a high quality and fine texture of the wool. These garments are part of a broader classification for men's or boys' suits, ensembles, and similar suit-type jackets and blazers.

The primary sibling category at this level is 6203.31.90, which encompasses "Other" suit-type jackets and blazers of wool or fine animal hair. Therefore, 6203.31.50 is distinguished by the specific requirement of worsted wool fabric with a fine fiber diameter, whereas the sibling category would cover garments made from other types of wool or fine animal hair, or those not meeting the precise micron specification.

Within 6203.31.50, further subdivision occurs to distinguish garments based on their intended use or integration within a suit. The subcategories 6203.31.50.10 and 6203.31.50.20 differentiate between jackets specifically designated for suits described under a particular note (likely referencing ensemble definitions or specific suit components) and all other such jackets that do not fall under that specific note. This granular breakdown allows for precise tariff application based on the intended final garment assembly.