Transformer and converter parts span a wide material spectrum — from grain-oriented silicon steel laminations and stacked cores (8504909634, 8504909638) to ferrite cores (8504909610, 8504909630) and printed circuit assemblies for ADP power supplies (8504902000) — making correct classification among the 14 active 10-digit lines a recurring challenge. Mexico leads US import supply, followed by Thailand and Canada, reflecting deep North American and Southeast Asian electronics supply chains. Ferrite and lamination components are particularly sensitive to Section 301 tariffs when sourced from China, and misclassification between transformer parts and static converter or inductor parts can trigger reclassification audits. Importers should maintain detailed bills of materials and engineering drawings to substantiate the specific part-type claimed.

AI-written summary of the official U.S. Census Bureau trade figures on this page — verify before relying on it.