7306.61.10.00 - Of iron or nonalloy steel

This HTS category, 7306.61.10.00, specifically classifies welded tubes, pipes, and hollow profiles made of iron or nonalloy steel that have a square or rectangular cross-section and a wall thickness of 4 millimeters or greater. The "nonalloy steel" designation signifies that the steel contains minimal amounts of alloying elements beyond those naturally present or intentionally added in small quantities for specific properties. These items are typically used in structural applications where strength and rigidity are paramount, such as construction, scaffolding, and heavy-duty framing.

This classification is distinguished from its sibling category, 7306.61.30.00, by the material composition. While both cover welded, non-circular hollow profiles with a wall thickness of 4 mm or more, 7306.61.30.00 applies to those manufactured from alloy steel. Alloy steels, by definition, contain significant additions of elements like chromium, nickel, manganese, or molybdenum to enhance properties such as corrosion resistance, hardness, or tensile strength, which are not characteristic of the iron or nonalloy steel covered here.

As this is a leaf node within the HTS, there are no further subcategories. Therefore, the classification is definitive for welded iron or nonalloy steel hollow profiles with a square or rectangular cross-section and a wall thickness of 4 mm or more. The key determinative factors for inclusion are the material (iron or nonalloy steel), the manufacturing method (welded), the cross-sectional shape (square or rectangular), and the substantial wall thickness (4 mm or greater).