8459.70.40.00 - Numerically controlled

This HTS subcategory, 8459.70.40.00, specifically covers numerically controlled (NC) machines designed for threading or tapping operations, distinct from other machine tools. These machines utilize programmed instructions to automate the process of cutting internal or external threads or creating screw threads within pre-drilled holes. The key characteristic is the integration of numerical control systems, which precisely direct the machine's movements and tool engagements, ensuring high accuracy and repeatability. Examples include NC tapping machines for creating internal threads in workpieces and NC die heads for generating external threads on rods or shafts.

The primary distinction from its sibling category, 8459.70.80 (Other), lies in the presence of numerical control. While both are "other threading or tapping machines," this subcategory is exclusively for those equipped with advanced NC systems. The sibling category would encompass simpler, non-numerically controlled threading and tapping machines, which might rely on manual operation, mechanical setups, or less sophisticated automated sequences. The defining factor for classification here is the sophisticated electronic and software-based control system that dictates the machining process.

As this is a leaf node within the HTS, there are no further subcategories for this specific code. Therefore, the classification relies on clearly identifying machines that perform threading or tapping functions and are operated via numerical control, differentiating them from general machining centers or non-NC threading equipment. The emphasis remains on the automated, programmed nature of the operation as the defining criterion for this classification.