</>Build with Tariff Intelligence|Programmatic access to tariff calculations and HS code classification.Explore Developer Resources →

Fluxing Calcareous Stone for Steel Mills from Japan

Coarse angular calcareous stone flux, sized 1-4 inches, used in steel mill basic oxygen furnaces to form slag and protect furnace linings. HTS 2521.00.00.00 covers this as limestone flux specifically for lime-related industrial processes. Its high melting point and impurity-binding properties define its metallurgical role.

Duty Rate — Japan → United States

12.5%

Rate breakdown

9903.05.4912.5%Section 301 (forced labor) — Japan (col1 rate < 12.5 percent): MFN < 12.5% → total duty capped at 12.5%

Import Tips

Include steel mill purchase orders referencing flux specifications to substantiate end-use for classification

Conduct sieve analysis to document flux sizing, preventing confusion with general crushed rock

Beware of blending with dolomite; mixtures may require separate classification under 2518