7305.19.10.30 - With an external diameter exceeding 406.4 mm but not exceeding 609.6 mm

This HTS category, 7305.19.10.30, specifically covers iron or steel tubes and pipes that are not of circular cross-section and are used for oil or gas pipelines. These pipes are characterized by having an external diameter that is greater than 406.4 mm but does not exceed 609.6 mm. The material composition is restricted to iron or nonalloy steel. Examples within this classification would include welded, riveted, or similarly closed pipes of these dimensions and material, intended for the transport of oil or gas.

The primary distinguishing feature of this category from its sibling, 7305.19.10.60, lies in the external diameter. While both categories concern line pipe of a kind used for oil or gas pipelines and are made of iron or nonalloy steel, 7305.19.10.30 applies only to those with an external diameter between 406.4 mm and 609.6 mm, whereas the sibling category covers pipes with an external diameter exceeding 609.6 mm. This precise dimensional threshold is crucial for accurate classification.

As this is a leaf node within the HTS, there are no further subcategories. Therefore, the classification relies entirely on the defined criteria of external diameter and the specific application as line pipe for oil or gas pipelines, along with the material of iron or nonalloy steel. Importers and exporters must carefully measure the external diameter and confirm the intended use to ensure correct classification under this specific HTS code.