7307.91.30.00 - Of alloy steel (except stainless steel)

This HTS classification, 7307.91.30.00, specifically covers fittings made from alloy steel, excluding stainless steel. These fittings are designed for use with tubes and pipes, serving crucial functions such as joining, diverting, or terminating fluid or gas pathways. Examples include elbows, tees, couplings, and flanges, all fabricated from alloy steel compositions that offer enhanced mechanical properties compared to plain iron or non-alloy steel, but do not possess the chromium content characteristic of stainless steel.

The distinction between this category and its sibling, 7307.91.10.00, lies solely in the material composition. While both fall under "Other" and "Flanges" (when not machined or tooled after forging), this heading is reserved for alloy steels, whereas the sibling is for iron or non-alloy steel. This material differentiation is a primary factor in determining the correct tariff classification.

As a leaf node in the HTS, this category does not have further subdivisions. Therefore, classification into 7307.91.30.00 is final for alloy steel (excluding stainless steel) flanges that have undergone no machining, tooling, or other processing after their initial forging. Importers and exporters should carefully verify the material composition of their goods to ensure accurate classification.