7305.12.10.30 - With an external diameter exceeding 406.4 mm but not exceeding 609.6 mm

This HTS category, 7305.12.10.30, specifically covers longitudinally welded tubes and pipes of iron or non-alloy steel that are intended for use in oil or gas pipelines. The defining characteristic for inclusion in this subcategory is their external diameter, which must fall within a precise range: exceeding 406.4 mm but not exceeding 609.6 mm. These pipes are typically employed in the transportation of oil and natural gas, and their structural integrity and dimensions are critical for such applications.

The distinction between this category and its sibling, 7305.12.10.60, lies solely in the external diameter. While both cover longitudinally welded line pipe of iron or non-alloy steel, 7305.12.10.60 applies to pipes with an external diameter exceeding 609.6 mm. Therefore, the specific diameter measurement is the sole determinant for correct classification between these two closely related subheadings.

As this is a leaf node, there are no further subdivisions within this specific classification. Classification terminates at this level based on the material (iron or non-alloy steel), the manufacturing method (longitudinally welded), the intended use (oil or gas pipelines), and the precise external diameter range. Any tubes or pipes falling outside this specified diameter range, or made of alloy steel, or not intended for pipeline use, would be classified under different HTS headings or subheadings.