7229.90.50.51 - With a diameter of 1.5 mm or more

This HTS classification covers round wire made from alloy steel that has a diameter of 1.5 millimeters or more. This category specifically includes wire where the smallest cross-sectional dimension meets or exceeds this threshold. The "other alloy steel" designation indicates that the steel composition deviates from standard carbon steel, containing additional alloying elements such as chromium, nickel, molybdenum, or vanadium, which impart specific properties like increased strength, corrosion resistance, or hardness.

The key differentiator for this classification, 7229.90.50.51, lies in the diameter. It is distinct from its siblings which cover wires with smaller diameters. Specifically, 7229.90.50.16 is for round alloy steel wire with a diameter less than 1.0 mm, and 7229.90.50.31 is for wire with a diameter of 1.0 mm or more but less than 1.5 mm. Therefore, imported or exported goods must be precisely measured to ensure correct classification.

As this is a leaf node within the HTS system, there are no further subdivisions under this specific code. Classification into 7229.90.50.51 is final based on the material (other alloy steel), form (round wire), and the critical diameter specification of 1.5 mm or greater. This granular detail ensures accurate duty assessment and trade statistics for these particular types of steel wire products.