Metal polishes are explicitly excluded from subheading 340530 (coachwork polishes) but can fall under 340590 as 'other' polishes and similar preparations within heading 3405, provided they are not more specifically classified elsewhere. The heading covers polishes for glass and metal among other surfaces under the residual subheading.

When a product is designed for multiple substrates covered by different subheadings, classification follows the subheading that best describes its principal use as presented. If no single use is clearly principal, the residual subheading 340590 is the appropriate fallback. Documentation of the product's marketed primary application can support the classification.