8459.51.00.40 - Used or rebuilt

This HTS category, 8459.51.00.40, specifically covers numerically controlled milling machines that are either used or rebuilt. These machines are designed for metal removal through milling operations and are characterized by their "knee-type" construction, meaning the worktable is supported by a vertical column through a knee. The "numerically controlled" designation signifies that their operations are automated and directed by pre-programmed commands, enabling high precision and repeatability in manufacturing processes. The inclusion of "used or rebuilt" indicates that the classification applies to machines that have been previously utilized and subsequently restored to operational condition, whether by the original manufacturer or a third party.

This category is distinguished from its sibling, 8459.51.00.80, which covers "Other" knee-type, numerically controlled milling machines. The primary distinction lies in the condition of the machine. While 8459.51.00.40 explicitly applies to machines that are used or have undergone rebuilding, the "Other" category would encompass new machines of this type. The focus on "used or rebuilt" for this specific code highlights the importance of the machine's history and its restoration status in the classification process, ensuring that these pre-owned but functional units are categorized appropriately for import and export purposes.

As this is a leaf node in the HTS classification structure, there are no further subcategories to introduce. Therefore, the classification is complete at this level for used or rebuilt knee-type, numerically controlled milling machines. The defining characteristics for classification here are the milling functionality, the knee-type configuration, numerical control, and the condition of being either used or rebuilt.