Boric Acid Welding Flux Powder from Mexico
Fine powder of boric acid and borates used as flux for oxyacetylene brazing of steel parts. Wholly inorganic composition prevents oxidation during high-heat joining, classified in 3810.90.2000 as auxiliary preparation for soldering/brazing. Common in HVAC repair.
Duty Rate — Mexico → United States
10%
Rate breakdown
9903.05.5510%Except for products described in headings 9903.05.85–9903.05.92 and 9903.05.94, articles the product of Mexico, as provided for in U.S. note 52 to this subchapter
Import Tips
• Certify boron content <15% water-soluble for non-hazardous shipping
• Provide AWS flux classification specs for customs verification
• Avoid bulk boric acid declaration; formulation specificity required