High-Efficiency UI Stacked Transformer Core from Mexico
UI-shaped silicon steel laminations stacked and hinged for easy assembly in high-efficiency transformers used in renewable energy inverters. These cores meet DOE efficiency standards when fully assembled. HTS 8504.90.96.38 covers such pre-stacked configurations.
Duty Rate — Mexico → United States
25%
Rate breakdown
9903.82.0925%Except as provided for in headings 9903.82.16, 9903.82.20–9903.82.26 and 9903.85.68, articles of copper and derivative aluminum and steel articles, as provided for in subdivisions (c)(vi)–(viii) and (xi) of U.S. note 16 to this subchapter
9903.05.900%Articles already subject to Section 232 (steel/aluminum/copper + derivatives, autos + parts, wood, medium/heavy vehicles + parts, semiconductors, patented pharma) — U.S. note 52(f)
Import Tips
• Efficiency class documentation (e.g
• NEMA standards) supports high-efficiency claims during customs review
• Hinge mechanism details must show temporary assembly only—no permanent fixtures for parts status
• Mark packages with 'For 50/60Hz transformer incorporation only' to prevent misuse classification