Solder wire composed primarily of tin — whether alloyed with lead, silver, or other metals — is generally classified here as tin wire if tin is the predominant metal by weight. However, if the alloy's composition shifts the predominant metal to another base metal, classification follows that metal's chapter. Confirming the alloy composition against the chapter notes is essential.

Heading 8003 covers bare wrought tin wire classified by its base-metal composition. Insulated wire and cable — regardless of the conductor metal — is classified in the chapter covering insulated wire, cable, and electrical conductors. A tin conductor that has been insulated or assembled into a cable moves out of this heading.