While clock cases as a category fall under this heading regardless of material, the specific material — wood, base metal, precious metal, plastic — can influence the applicable duty rate at the tariff-line level and may trigger separate valuation or marking requirements. Importers should declare the predominant material accurately and confirm the correct subheading with a customs broker, especially for cases combining multiple materials.

Parts specifically designed for clock cases — including bezels, crystals, and decorative panels — are generally classified within this heading when they are identifiable as clock-case parts. Generic glass or metal components not specifically adapted for clock cases may classify under their own material-based headings. The specificity of the part's design and its commercial description are the key factors.