7318.15.60 - Having shanks or threads with a diameter of less than 6 mm

This category encompasses screws and bolts of iron or steel, excluding those specifically detailed elsewhere, where the shank or thread possesses a diameter measuring less than 6 millimeters. This specific diameter limitation is the primary distinguishing characteristic for items falling under this classification. These fasteners are designed for joining materials and are prevalent across a wide range of manufacturing, construction, and general assembly applications.

Crucially, this HTS code differentiates itself from its sibling category, 7318.15.80, based solely on the diameter of the shank or thread. Items classified under 7318.15.60 will have a diameter strictly below 6 mm, whereas those under 7318.15.80 will be 6 mm or greater. Both categories fall under the broader heading for "Other screws and bolts, whether or not with their nuts or washers," and then further under "Other" threaded articles.

Within this classification, further subdivisions exist to refine the categorization of these smaller diameter screws and bolts. These subcategories include "Socket screws," which are characterized by a hexagonal socket in the head for driving with a hex key, and "Other," which captures all remaining types of screws and bolts with shanks or threads less than 6 mm in diameter that do not fit the specific definition of a socket screw.