8406.90.40.00 - Blades, rotating or stationary

HTS code 8406.90.40.00 specifically covers blades designed for steam turbines and other vapor turbines, which are either rotating or stationary in their function. This classification is for the individual blade components themselves, irrespective of their finished state for assembly or preliminary processing.

This category is distinguished from its sibling categories by its focus solely on the turbine blades. HTS 8406.90.20.00, for instance, pertains to finished rotors ready for final assembly, implying a more complete component than just individual blades. Similarly, HTS 8406.90.30.00 covers rotors that have undergone only basic finishing processes like cleaning or machining for defect removal, whereas 8406.90.40.00 is dedicated to the blades themselves. The broader category 8406.90.45, "Other," would encompass any remaining parts of steam turbines not specifically enumerated in the preceding subheadings.

As this subheading represents a leaf node within the HTS, there are no further subcategories. Therefore, classification under 8406.90.40.00 is determined by the item's identity as a turbine blade and its intended use in steam or vapor turbine machinery. Practical considerations for classification will focus on the physical form, material, and design characteristics of these blades.