7305.12 - Other, longitudinally welded:

This HTS category, 7305.12, specifically covers other longitudinally welded tubes and pipes of iron or steel, with a circular cross-section and an external diameter exceeding 406.4 mm. The defining characteristic here is the method of longitudinal welding, distinguishing it from categories that employ different welding techniques.

Within the broader classification of "Other tubes and pipes," this node is a subcategory of "Line pipe of a kind used for oil or gas pipelines." It differentiates itself from its sibling, 7305.11, which exclusively covers longitudinally submerged arc welded pipe. Therefore, 7305.12 encompasses all other forms of longitudinal welding not specified under submerged arc welding.

The subcategories under 7305.12 further refine the classification based on material composition. 7305.12.10 applies to pipes made of iron or nonalloy steel, while 7305.12.50.00 is designated for pipes manufactured from alloy steel. This distinction is crucial for determining applicable duties and trade regulations based on the specific metallic makeup of the pipe.