6105.90.40.00 - Containing 70 percent or more by weight of silk or silk waste (738)

This HTS classification, 6105.90.40.00, specifically covers knitted or crocheted shirts for men or boys that are predominantly made of silk or silk waste. The defining characteristic for inclusion in this category is that the textile component must comprise 70 percent or more by weight of silk or silk waste. This emphasis on silk content is crucial for accurate classification within the broader group of men's or boys' shirts made from "other textile materials."

Distinguishing this category from its siblings is essential. Unlike subcategory 6105.90.10.00, which is designated for shirts made of wool or fine animal hair, or the residual category 6105.90.80 for "other" textile materials, this specific classification isolates garments based on their high silk content. Therefore, any shirt falling under 6105.90.40.00 must meet the stringent 70% silk threshold, differentiating it from garments composed primarily of other fibers.

As this is a leaf node within the HTS structure, there are no further subcategories. The classification concludes at this point, meaning that all knitted or crocheted men's or boys' shirts containing 70 percent or more by weight of silk or silk waste will be classified under 6105.90.40.00. For import and export purposes, this specific designation ensures consistent treatment for these silk-rich apparel items.