7019.90.51.20 - Glass fibers in bulk

This HTS classification, 7019.90.51.20, specifically designates "Glass fibers in bulk." This category encompasses loose, unformed glass fibers, often referred to as glass wool or spun glass. These materials are characterized by their fine, filamentous structure and are typically produced by melting glass and then extruding or blowing it into a fibrous form. The primary intended use of these bulk fibers is as raw material for manufacturing other glass fiber articles, such as insulation, reinforcing materials, or filtration media, rather than as finished products themselves.

Distinguishing this category from its siblings, 7019.90.51.40 covers "Glass fiber filters," which are pre-formed articles designed for filtration purposes, and 7019.90.51.50, which covers "Other" glass fiber articles that do not fit into the more specific subcategories. Therefore, 7019.90.51.20 is reserved for the raw, unfabricated form of glass fibers before they are processed into more specialized items.

As this is a leaf node within the HTS, there are no further subcategories for this specific code. The classification for glass fibers in bulk is a terminal point, meaning that goods fitting this description will not be further broken down under this particular HTS number. Classification at this level focuses on the physical form and bulk nature of the glass fibers, serving as a foundational category before other processing or manufacturing steps take place.