9111.20 - Cases of base metal, whether or not gold- or silver-plated:

This HTS category, 9111.20, encompasses watch cases specifically constructed from base metals, which may or may not have been plated with gold or silver. Base metals, in this context, refer to metals other than precious metals, such as steel, brass, aluminum, and alloys thereof. The defining characteristic here is the material of the case itself, where the primary constituent is a base metal.

When classifying watch cases, it is crucial to distinguish this category from its siblings. HTS code 9111.10.00.00 covers cases made of precious metal or metal clad with precious metal, which are distinct due to their higher intrinsic value and material composition. Furthermore, 9111.80.00.00 addresses "other cases" not otherwise specified, implying that if a case is not of precious metal and not a base metal case (regardless of plating), it would fall under that broader category.

Within the 9111.20 category, further subclassification is provided to account for the specific type of plating. The subcategory 9111.20.20.00 specifically covers cases where the base metal has been plated with gold or silver. Conversely, 9111.20.40.00 applies to cases made of base metal that are not gold- or silver-plated, or are plated with other non-precious metals. This distinction allows for more granular reporting based on the finishing of the watch case.