4412.51 - With at least one outer ply of tropical wood:

This HTS category, 4412.51, specifically covers plywood and similar laminated wood products that feature at least one outer ply made from tropical wood. This designation includes a variety of panel materials where thin sheets of wood are glued together with adjacent layers having their grain rotated by 90 degrees. The defining characteristic for classification under this heading is the presence of an outer veneer layer derived from tropical hardwood species.

Distinguishing this category from its siblings is crucial for accurate classification. Unlike 4412.52, which covers similar laminated wood where at least one outer ply is nonconiferous (but not necessarily tropical wood), or 4412.59, which mandates both outer plies be of coniferous wood, 4412.51 is narrowly defined by the origin of its tropical wood veneers. Therefore, the identification of the wood species used for the outer layers is the primary determinant for differentiating these subheadings.

Within this category, further subdivisions exist to refine the classification. The subheading 4412.51.51.00 addresses "Other" plywood and laminated wood. This implies that within the broader scope of "at least one outer ply of tropical wood," there are more specific criteria or common product types that fall under this particular sub-designation, likely related to construction, thickness, or intended end-use.