9017.90.01.40 - Of articles of subheading 9017.30.40

This HTS category, 9017.90.01.40, specifically covers parts and accessories for instruments classified under subheading 9017.30.40. Subheading 9017.30.40 pertains to surveying, meteorological, hydrological, and geophysical instruments, including their parts and accessories. Therefore, this classification applies to components, attachments, or replacement pieces designed for use with instruments such as theodolites, levels, total stations, barometers, anemometers, rain gauges, and seismographs.

To differentiate this category from its siblings, it is crucial to understand that each sibling is also designated for parts and accessories of specific, different subheadings within heading 9017. For instance, sibling categories like 9017.90.01.05 and 9017.90.01.15 refer to parts of articles falling under 9017.10.40 and 9017.10.80, respectively, which generally cover drafting machines and drawing instruments. Similarly, other siblings are linked to different types of drawing, marking-out, or mathematical calculating instruments. The key differentiator for 9017.90.01.40 is its exclusive association with the surveying and scientific instrument subcategory of 9017.30.40.

As this is a leaf node within the HTS structure, there are no further subdivisions under 9017.90.01.40. Classification into this category will depend on the direct link of the part or accessory to the specific instruments described in subheading 9017.30.40. Practical classification will rely on determining if the part's function is intrinsically tied to the operation, measurement, or maintenance of surveying, meteorological, hydrological, or geophysical instruments.