8406.90 - Parts:

This HTS category, 8406.90, specifically covers parts that are not themselves turbines but are designed to be used with steam turbines and other vapor turbines classified under heading 8406. This encompasses a wide array of components, such as blades, rotors, casings, seals, bearings, lubrication systems, control mechanisms, and any other individual pieces necessary for the construction, repair, or maintenance of these turbines. The key criterion for inclusion is that the part must be intended for use with a turbine covered by heading 8406 and not be a complete turbine itself.

Distinguishing this category from its siblings, 8406.10, is crucial. While 8406.10 covers complete turbines specifically designed for marine propulsion, this category, 8406.90, is solely for the constituent parts of *any* steam or vapor turbine falling under heading 8406, regardless of its ultimate application. Therefore, if an item is a functional turbine for marine use, it would be classified under 8406.10, whereas a spare blade for that same turbine would fall under 8406.90.

Within this "Parts" category, further subclassification exists to differentiate the origin of the parts. The subcategories "Of steam turbines" and "Other" allow for a more granular breakdown based on the specific type of turbine to which the part belongs. This distinction is important for statistical tracking and can sometimes influence specific import/export regulations or duties depending on the type of vapor turbine.