7306.61.30.00 - Of alloy steel

This HTS classification, 7306.61.30.00, specifically covers welded tubes, pipes, and hollow profiles of iron or steel that have a square or rectangular cross-section, a wall thickness of 4 millimeters or more, and are made from alloy steel. The "alloy steel" designation is critical here, differentiating these articles from those made of plain iron or non-alloy steel, which would fall under a different subheading.

The defining characteristics for this category are the welded construction, the non-circular (specifically square or rectangular) cross-section, a substantial minimum wall thickness of 4 mm, and the composition of alloy steel. Alloy steel, by definition, contains specific amounts of alloying elements such as nickel, chromium, molybdenum, or vanadium, which are added to enhance properties like strength, hardness, or corrosion resistance.

As this is a leaf node in the HTS classification system, there are no further subdivisions under this code. Therefore, the focus for classification rests entirely on meeting all the preceding criteria: welded, square/rectangular cross-section, wall thickness of 4 mm or more, and being made of alloy steel. Importers and exporters must ensure the technical specifications of their goods precisely match these requirements to ensure correct customs declaration and duty assessment.