Single Uncombed Cotton Yarn, 85%+ Cotton, Not for Retail, Over 43 Nm to 52 Nm

Mercerized yarn has been treated with caustic soda under tension, improving luster, strength, and dye uptake. The US tariff schedule distinguishes mercerized from unbleached/unmercerized yarn at the 10-digit level within this subheading, so importers must confirm the finishing treatment with the mill to select the correct line and avoid post-entry corrections.

Both spinning methods are used, but open-end (rotor) spinning is more common at coarser counts, while ring spinning becomes more prevalent as counts increase toward 52 Nm. The spinning method affects yarn strength and surface character, which downstream weavers specify — and some 10-digit lines within related subheadings explicitly distinguish ring-spun from other constructions.