5510.90.40.00 - Multiple (folded) or cabled yarn (607)

This HTS category, 5510.90.40.00, encompasses multiple (folded) or cabled yarns made from artificial staple fibers. These yarns are not intended for retail sale and are characterized by the twisting of two or more single yarns together or by twisting single yarns multiple times to create a thicker, stronger, or more decorative yarn. The "artificial staple fibers" component is crucial, indicating that the fibers are man-made and cut or broken into lengths similar to natural staple fibers, rather than being continuous filament.

Distinguishing this category from its sibling, 5510.90.20.00 (single yarn), is the construction. While both are yarn of artificial staple fibers not put up for retail sale and not mixed with synthetic staple fibers, 5510.90.20.00 refers to yarn made from a single strand of artificial staple fiber, whereas 5510.90.40.00 specifically covers yarns formed by combining multiple single strands or by multiple twisting. The parent category, "Yarn (other than sewing thread) of artificial staple fibers, not put up for retail sale: Other yarn: Mixed mainly or solely with synthetic staple fibers," further clarifies that this yarn should not be primarily composed of synthetic fibers.

As a leaf node, this HTS code does not have further subcategories. Therefore, classification within 5510.90.40.00 is determined by the presence of multiple or cabled construction of artificial staple fiber yarn, not put up for retail sale, and not predominantly mixed with synthetic staple fibers. Examples would include two-ply or three-ply yarns of rayon staple or acetate staple, or cabled yarns of these materials, intended for industrial or manufacturing use.