8458.91 - Numerically controlled:

This HTS classification, 8458.91, specifically covers "numerically controlled" lathes, which are a subset of "other lathes" for removing metal. These machines are characterized by their advanced automation, where tool movements and operations are controlled by pre-programmed numerical data. This allows for high precision, repeatability, and the ability to perform complex machining operations. The "numerically controlled" aspect is the primary distinguishing feature, setting them apart from manual or less automated lathe types.

Within the broader category of "other lathes," 8458.91 focuses exclusively on those equipped with numerical control systems. This differentiates them from their sibling category, 8458.99, which encompasses all other lathes not equipped with such advanced control technology. The classification is determined by the presence and functionality of the numerical control system, irrespective of other specific features such as the orientation of the spindle or the type of workpiece handled.

To further refine classification, HTS 8458.91 is divided into subcategories based on specific configurations. 8458.91.10 identifies "Vertical turret lathes," a design where the workpiece rotates on a horizontal axis and the cutting tools are mounted on a vertical turret. The residual category, 8458.91.50, "Other," captures all other types of numerically controlled lathes that do not fit the specific description of vertical turret lathes, encompassing a variety of designs such as horizontal lathes with numerical control.