8466.10.01 - Tool holders and self-opening dieheads

HTS Code 8466.10.01 specifically classifies tool holders and self-opening dieheads. Tool holders are essential components designed to securely grip and position cutting tools, forming tools, or other implements used in machining operations. Self-opening dieheads are specialized attachments used in metalworking to automatically open or retract during threading operations, thereby improving efficiency and precision. These items are integral to the functioning of machinery within headings 8456 to 8465, acting as critical interfaces between the machine and the workpiece or tool.

This category is distinguished from its siblings, 8466.20 (Work holders) and 8466.30 (Dividing heads and other special attachments for machines), by its focus on the items that directly hold the *tool* or facilitate its automatic operation during a cutting or forming process. While work holders (8466.20) secure the workpiece, and dividing heads (8466.30) are used for indexing and positioning workpieces or tools for operations like milling or drilling, 8466.10.01 is concerned with the mechanisms that firmly engage and control the *tool itself* or the automatic release of a threading tool.

Within HTS Code 8466.10.01, further subcategories exist to provide more granular classification based on the specific type of tool holder or diehead. These include "Tool holders for forming-type or cutting-type dies," which are designed to hold dies used in metal forming or cutting processes; "Holders for replaceable cutting or drill inserts," which accommodate interchangeable inserts for machining; and "Other" for tool holders and self-opening dieheads not specifically covered by the preceding subdivisions. This breakdown allows for precise identification of the item's function and application.