7318.21.00.30 - Helical spring lock washers

This HTS category, 7318.21.00.30, specifically covers helical spring lock washers manufactured from iron or steel. These washers are designed with a characteristic spiral or helical shape, which creates a spring-like action when compressed between a bolt or screw head and the surface of the material being fastened. This spring action is intended to exert a continuous tension, preventing loosening due to vibration or thermal expansion.

Within the broader classification of "Spring washers and other lock washers," this subcategory is distinguished from its sibling category, 7318.21.00.90 ("Other"), by its specific helical construction. While "other" lock washers might encompass a variety of designs intended for similar purposes, this heading is exclusively for those featuring a helical, or coiled, spring configuration. This distinction is crucial for accurate customs declaration, ensuring that the precise type of lock washer is identified.

As this is a leaf node in the HTS classification, there are no further subdivisions. Therefore, the classification is complete at this level. When classifying articles under this code, the primary considerations are the material (iron or steel) and the distinctive helical spring design of the washer, as opposed to other types of lock washers such as split or toothed washers.