5101.19.40.00 - Other wool, finer than 40s but not finer than 44s

This HTS classification, 5101.19.40.00, specifically encompasses greasy wool that is not carded or combed and falls within a particular fineness range. Unlike other categories at this level, the wool classified here is not of the "unimproved" type and has a fineness exceeding 40s but not exceeding 44s. This precise micron count or diameter is a key determinant for classification, ensuring that only wool meeting these exact specifications is included.

This category is distinct from its siblings by its defined fineness. The sibling category 5101.19.20.00 covers wool that is not finer than 40s, while 5101.19.50.00 deals with wool finer than 44s. Therefore, 5101.19.40.00 acts as a crucial intermediary, capturing wool that is specifically finer than 40s but stops short of the finer grades classified in the subsequent sibling category.

As this is a leaf node within the HTS structure, there are no further subcategories. All eligible products fitting the description of "Other wool, finer than 40s but not finer than 44s" that are greasy and not carded or combed will terminate at this classification point. Classification relies heavily on the documented fineness of the wool, which is typically determined through laboratory testing.