Mercury Arc Rectifier Gas Tube from China
Mercury arc rectifier tubes convert AC to DC using ionized mercury vapor in a vacuum envelope, historically used in industrial power supplies. Though largely obsolete, they remain classified as gas-filled electron tubes under HTS 8540.89.0020.
Duty Rate — China → United States
38.7%
Rate breakdown
9903.03.0110%Except for products described in headings 9903.03.02–9903.03.11, articles the product of any country, as provided for in subdivision (aa) of U.S. note 2 to this subchapter
9903.88.0125%Except as provided in headings 9903.88.05, 9903.88.06, 9903.88.07, 9903.88.08, 9903.88.10, 9903.88.11, 9903.88.14, 9903.88.19, 9903.88.50, 9903.88.52, 9903.88.58, 9903.88.60, 9903.88.62, 9903.88.66, 9903.88.67, 9903.88.68, or 9903.88.69, articles the product of China, as provided for in U.S. note 20(a) to this subchapter and as provided for in the subheadings enumerated in U.S. note 20(b) [to this subchapter]
Import Tips
• Declare mercury content accurately due to hazardous material shipping requirements
• Provide proof of intended industrial/legacy use vs. modern semiconductor replacement
• EPA import notifications required for mercury-containing tubes