3810.90Subheading
Fluxes and other auxiliary preparations; for soldering, brazing or welding, or preparations used as cores or coatings for welding electrodes or rods
Section VI — Products of the chemical or allied industries
This is a 6-digit subheading — the most specific level of the international HS. Country tariff schedules extend it further; the US tariff lines (HTS) below refine it to 8–10 digits for duty purposes.
US tariff lines for this subheading are not in the bundled starter dataset yet — the full HTS schedule is coming soon. You can still search by code in the tariff simulator.