8412.90 - Parts:

This HTS category, 8412.90, encompasses parts specifically designed for use with other engines and motors falling under heading 8412. This includes components such as housings, shafts, pistons, cylinders, gears, and other internal or external elements integral to the functioning of various engine and motor types not otherwise specified in the heading. The classification is contingent on the part's direct and essential relationship to the operation of an engine or motor within the 8412 scope, rather than its use in a broader mechanical assembly.

While other categories within heading 8412 cover complete engines and motors, such as reaction engines (8412.10), hydraulic power engines and motors, pneumatic power engines and motors, and other miscellaneous engines and motors (8412.80), this category 8412.90 is exclusively for the constituent parts of these devices. For instance, a complete hydraulic motor would be classified under the relevant subcategory of 8412.21 to 8412.29, whereas a replacement pump or valve specifically for that motor would fall under 8412.90.

The subcategories within 8412.90 provide further specificity based on the type of engine or motor the part belongs to. 8412.90.10.00 specifically identifies parts for hydrojet engines used in marine propulsion, distinguishing them due to their unique design and application in that specific context. The residual category, 8412.90.90, covers all other parts for engines and motors under heading 8412 that are not specifically enumerated in the preceding subcategory, serving as a general classification for the remaining components.