5107.20 - Containing less than 85 percent by weight of wool:

This HTS category, 5107.20, covers yarn of combed wool that is not put up for retail sale and contains less than 85 percent by weight of wool. The "less than 85 percent" criterion is crucial here, distinguishing it from yarns where wool is the predominant component. These yarns are intended for further manufacturing or industrial use rather than direct sale to consumers.

The primary distinction from its sibling, HTS 5107.10, lies in the wool content. While 5107.10 exclusively covers combed wool yarns with 85 percent or more wool by weight, this category, 5107.20, encompasses those yarns where wool is present but constitutes less than 85 percent of the total weight. This implies the presence of other fibers mixed with the wool in the yarn.

Within 5107.20, two subcategories further refine the classification based on the characteristics of the wool fiber. The first, 5107.20.30.00, specifically addresses yarns made from wool fiber with a fine average diameter of 18.5 microns or less. This indicates a focus on fine wool qualities. The second, 5107.20.60.00, serves as a residual category for all other combed wool yarns that meet the "less than 85 percent wool" criteria but do not fall into the finer fiber diameter classification.