7305.39.10.00 - Of iron or nonalloy steel

This classification covers large-diameter tubes and pipes, specifically those manufactured from iron or nonalloy steel. These articles are characterized by having a circular cross-section with an external diameter exceeding 406.4 millimeters. They are further defined by their method of construction, being welded, riveted, or similarly closed. The primary material composition, being of iron or nonalloy steel, is a crucial determinant for inclusion in this category.

This category, "Of iron or nonalloy steel" (7305.39.10.00), is distinguished from its sibling, "Of alloy steel" (7305.39.50.00), by the precise composition of the base metal. While both categories fall under "Other, welded" tubes and pipes with circular cross-sections exceeding 406.4 mm in diameter, the key differentiator lies in the steel's alloy content. Articles classified here must not contain significant alloying elements as defined by HTS provisions for alloy steel.

As a leaf node, this classification does not have further subcategories. Therefore, its scope is definitive for large-diameter welded tubes and pipes of iron or nonalloy steel. Practical classification will rely on confirming the absence of alloying elements beyond those permitted for nonalloy steel and verifying the specified diameter and welded construction, aligning with the broader context of "Other tubes and pipes" under HTS heading 7305.