7409.90 - Of other copper alloys:

This category, HTS 7409.90, encompasses plates, sheets, and strip of copper alloys, specifically those not falling under the preceding subheadings within 7409. This exclusion applies to alloys primarily composed of refined copper, copper-zinc (brass), copper-tin (bronze), and copper-nickel base alloys. The key defining characteristic is the material composition, focusing on the diverse range of copper alloys beyond the specifically enumerated types, provided the article meets the thickness criteria of exceeding 0.15 mm.

Distinguishing 7409.90 from its siblings is crucial for accurate classification. While siblings like 7409.10 cover refined copper, and 7409.21/7409.29 address copper-zinc and copper-tin alloys respectively, this subheading acts as a residual category for other copper alloy compositions. Similarly, 7409.40 pertains to copper-nickel alloys. Therefore, if a copper alloy product does not fit neatly into those more specific alloy types, it will likely be classified under 7409.90, provided it is in the form of a plate, sheet, or strip exceeding 0.15 mm.

The subcategories under 7409.90 further refine the classification based on physical dimensions, specifically thickness. The subsequent subdivisions differentiate between products of a thickness of 5 mm or more and those of a thickness less than 5 mm. This distinction allows for more precise tariff application based on the significant difference in the physical form and potential end-use applications associated with these varying thicknesses.