Metal gaskets constructed as described in heading 8484 are classified in subheading 8484.10 (i.e. ), regardless of application (you may refer to to see related descriptions). The classification of other gaskets with an essential character of metal depends on their use. If they are solely or principally used as parts of articles provided for in Section XVI or Chapter 90, they would be classified under the appropriate parts provision. If they are not solely or principally used as parts of articles which are described in Section XVI or Chapter 90, they would be classified under the applicable “articles of” provision covering the metal from which they are made, e.g., subheading 7326.90, HTSUS, for steel gaskets, subheading 7419.99, for copper gaskets, subheading 7616.99, HTSUS, for aluminum gaskets, etc.