8459.21.00.40 - Used or rebuilt

This HTS category, 8459.21.00.40, specifically covers **used or rebuilt numerically controlled drilling machines**. These machines are designed for metal removal operations through drilling, and their operation is guided by pre-programmed numerical commands, making them highly automated and precise. The "used or rebuilt" designation is crucial, distinguishing these items from new machinery that would fall under different subheadings.

Within the broader classification of "Other drilling machines," this subheading is distinct from its sibling category 8459.21.00.80, which covers "Other" numerically controlled drilling machines that are not specified as used or rebuilt. Therefore, the primary differentiating factor is the condition of the machinery.

As this is a leaf node, there are no further subcategories under 8459.21.00.40. Classification at this level relies on the confirmed condition of the drilling machine being either previously used or having undergone a rebuilding process, in addition to meeting the criteria for being numerically controlled. Examples might include reconditioned drilling machines that have been restored to full operational capacity for industrial use.