Helium-3/Helium-4 Mixture (Dilution Grade) from China
Pre-mixed He-3/He-4 solution at ~3-10% He-3 concentration for dilution refrigerator stills. The isotopic content qualifies under HTS 2845.40.00.00 as enriched helium isotopes. Used directly in cryostats for phase separation cooling.
Duty Rate — China → United States
35%
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
• Specify exact molar ratio on invoice; use Dewar shipping with temp monitoring; verify mixture doesn't exceed chemical preparation thresholds