8109.91.00.00 - Containing less than 1 part hafnium to 500 parts zirconium by weight

This HTS classification, 8109.91.00.00, specifically covers zirconium materials that contain less than one part hafnium for every 500 parts zirconium by weight. This precise ratio is the defining characteristic for goods falling under this heading, distinguishing them from other zirconium-based products. These items are generally processed zirconium in various forms, such as powders, bars, rods, wires, or sheets, intended for further manufacturing or direct use where a high degree of hafnium purity (relative to zirconium) is not required, or where its presence is minimized to meet specific technical or regulatory standards.

It is important to differentiate this category from its sibling, 8109.99.00.00, which encompasses all other zirconium articles not meeting the strict hafnium-to-zirconium weight ratio defined here. The key differentiator is the quantitative limit on hafnium content. Products classified under 8109.91.00.00 must demonstrably meet the specified low hafnium concentration.

As a leaf node within the HTS structure, 8109.91.00.00 does not have further subcategories. Therefore, classification within this code relies entirely on accurately confirming the material composition according to the stated weight ratio of hafnium to zirconium. Importers and exporters should ensure that their documentation clearly substantiates this purity level through appropriate analytical testing or supplier certifications to ensure correct customs declaration.