3917.40.00 - Fittings

This HTS category, 3917.40.00, specifically encompasses "Fittings" made from plastics, designed for use with tubes, pipes, and hoses. These fittings serve crucial roles in connecting, directing, or terminating fluid or air transfer systems constructed from plastic materials. Examples include couplings, adapters, elbows, tees, flanges, and connectors.

Distinguishing this category from its siblings, 3917.10 and the broader categories for "Tubes, pipes and hoses, rigid" and "Other tubes, pipes and hoses," is essential. While the siblings cover the conduits themselves, 3917.40.00 is exclusively for the components that join, alter the direction of, or terminate these conduits. The material composition must be plastic, aligning with Chapter 39's scope.

Within this fitting category, further subdivisions exist to provide granular classification. Subcategories like those for brake hose fittings (3917.40.00.10) highlight specific applications for specialized fittings, often dictated by performance or regulatory requirements. Other subdivisions may delineate based on function, such as plumbing fittings (both pressure-rated and non-pressure-rated like Drain/Waste/Vent systems), or a general "Other" category for fittings not otherwise specified. This structure allows for precise tariff application based on the fitting's intended use and design.