7409.31 - In coils:

This HTS category, 7409.31, specifically classifies copper-tin base alloy (bronze) plates, sheets, and strip, provided they are supplied in coils and have a thickness exceeding 0.15 mm. The defining characteristic here is the composition of the base metal alloy, which must be primarily copper with tin as the principal alloying element, forming what is commonly known as bronze. These items are typically used in various industrial applications where the properties of bronze, such as its strength, corrosion resistance, and conductivity, are advantageous.

It's crucial to distinguish this category from its sibling, 7409.39, which covers other bronze plates, sheets, and strip not supplied in coils. Therefore, if the bronze product is presented in a form other than coils, such as cut pieces or individual sheets, it would fall under the sibling category. The classification hinges directly on the method of presentation.

Within 7409.31, further subdivisions are made based on specific thickness parameters, allowing for more precise classification. The subcategories differentiate between bronze coils of a thickness of 5 mm or more and those with a thickness of less than 5 mm. This distinction is important for trade statistics and potentially for applying different duty rates or import regulations based on the dimensional characteristics of the material.