7304.19.50.80 - Having an outside diameter exceeding 406.4 mm

This HTS category, 7304.19.50.80, specifically classifies seamless tubes and pipes of iron or steel, intended for use as line pipe in oil or gas pipelines. These articles are characterized by being made of "other alloy steel" and, crucially, possess an outside diameter that exceeds 406.4 mm. This size threshold is the defining characteristic for this particular subcategory.

The distinction between this category and its siblings lies solely in the specified outside diameter. 7304.19.50.20 covers similar line pipe with an outside diameter not exceeding 114.3 mm, while 7304.19.50.50 encompasses those with an outside diameter exceeding 114.3 mm but not exceeding 406.4 mm. Therefore, the classification hinges on accurately measuring the external circumference of the pipe, ensuring it surpasses the 406.4 mm benchmark to fall into this specific code.

As this is a leaf node within the HTS, there are no further subdivisions under this code. Classification concludes at this level, with the determination being that the article is a seamless line pipe of other alloy steel with an outside diameter exceeding 406.4 mm. Examples of such pipes would include large-diameter steel conduits used for transporting crude oil or natural gas over long distances, where robust construction and significant capacity are paramount.