7019.90.51.40 - Glass fiber filters

This HTS code, 7019.90.51.40, specifically classifies "Glass fiber filters." These are articles manufactured from glass fibers, designed and constructed with the primary function of filtering particulate matter from liquids or gases. This can include a wide array of filtration media, such as those used in industrial processes, air purification systems, or water treatment. The key defining characteristic is their intended use as a filtering element.

Distinguishing this category from its siblings, 7019.90.51.20 covers glass fibers in bulk form, which are raw or loosely processed glass fibers not yet assembled into a finished filtering article. The sibling 7019.90.51.50, "Other," would encompass other miscellaneous articles of glass fiber that do not fit into the more specific classifications, such as filter media. Therefore, 7019.90.51.40 is reserved for the complete, functional filter units themselves.

As this classification is a leaf node, there are no further subcategories. Classification under 7019.90.51.40 relies on the product being definitively manufactured from glass fibers and possessing the inherent structure and purpose of a filter. This excludes raw materials, semi-finished goods, or other finished glass fiber articles not intended for filtration.