Multiple/Cabled Combed Cotton Blend Yarn, Not for Retail Sale, 52–80 NM

Within the cotton yarn headings, metric number per single yarn is the primary subdivision criterion after fiber content and twist structure. A yarn measured at 52 NM falls at the boundary between 520643 and 520644; importers should obtain certified NM test results from the spinner to avoid misclassification and potential duty disputes.

Yes — combed and carded yarns are classified in separate HS subheadings throughout chapter 52. Combed yarn undergoes an additional processing step that removes short fibers, producing a smoother, stronger yarn. Misidentifying a carded yarn as combed (or vice versa) constitutes a classification error; mill process documentation or fiber analysis can confirm the distinction.