7304.90.70.00 - Of alloy steel

This HTS category, 7304.90.70.00, specifically classifies seamless tubes, pipes, and hollow profiles made from **alloy steel**. These articles are distinguished by their composition, containing intentionally added elements beyond iron and carbon to enhance their properties, such as increased strength, hardness, corrosion resistance, or heat resistance. The "other" designation within 7304.90 signifies that these are not cast iron and not specifically covered by other subheadings within the seamless category of iron or steel tubes.

The critical distinguishing factor for this category, compared to its sibling 7304.90.50.00 ("Of iron or nonalloy steel"), lies in the material composition. While both cover seamless tubes and pipes with a wall thickness less than 4 mm, this subheading mandates the use of alloy steel, whereas the sibling covers those made from iron or standard nonalloy steel. The presence of alloying elements is the decisive criterion for classification under 7304.90.70.00.

As this is a leaf node, there are no further subcategories for this specific HTS code. Therefore, classification under 7304.90.70.00 is definitive once it has been established that the article is a seamless tube, pipe, or hollow profile of iron or steel, not of cast iron, with a wall thickness less than 4 mm, and crucially, is made of alloy steel. Examples within this category could include alloy steel mechanical tubing used in automotive components or alloy steel fluid power tubing for specialized industrial applications.