Wool tops are continuous, parallel-fiber slivers wound onto a package and ready for worsted spinning, classified under 510529. Combed wool in fragments (510521) refers to shorter, discontinuous combed fiber that has not been formed into a continuous top — essentially the intermediate output before top formation. The distinction matters for mill purchasing and for correct tariff-line classification.

Raw, unprocessed cashmere that has not been carded or combed is classified under heading 5102. Once it has been carded or combed — aligning the fibers for spinning — it moves to 510531 under this heading. The processing step, not the fiber type, determines which heading applies.