3810.90.20.00
Consisting wholly of inorganic substances
Classification path
- Pickling preparations for metal surfaces; fluxes and other auxiliary preparations for soldering, brazing or welding; soldering, brazing or welding powders and pastes consisting of metal and other materials; preparations of a kind used as cores or coatings for welding electrodes or rods
- Other
- Consisting wholly of inorganic substances
Rates of duty
- General (MFN)
- Free
- Column 2Cuba, North Korea, Russia, Belarus
- 25%
- Unit of quantity
- kg
Related lines in heading 3810
About heading 3810
Pickling preparations for metal surfaces; fluxes and other auxiliary preparations for soldering, brazing or welding; soldering, brazing or welding powders and pastes consisting of metal and other materials; preparations of a kind used as cores or coatings for welding electrodes or rods
Heading 3810 covers chemical preparations used with metal: pickling preparations for cleaning metal surfaces, fluxes and auxiliary preparations for soldering, brazing or welding, metal-bearing soldering and brazing powders and pastes, and preparations used as cores or coatings for welding electrodes. The heading splits first at 3810.10, which takes pickling preparations and metal-containing soldering, brazing or welding powders and pastes. Everything else falls in 3810.90, split by aromatic content, then by whether the preparation consists wholly of inorganic substances, then a residual line.
Full guide to heading 3810Products in this heading
- Soldering flux paste for electronics repair
- Brazing flux powder for copper pipe joints in HVAC work
- Stainless steel pickling solution for weld cleanup and descaling
- Solder paste made of metal powder blended with flux for reflow
- Coating mixture applied to welding electrode coatings
- Core powder used inside flux-cored welding wire
- Aluminum brazing flux for heat exchanger assembly
- Tinning paste used to prepare metal surfaces before soldering
Frequently asked questions
What is the HTS code for soldering flux?
Fluxes for soldering fall in 3810.90. A flux consisting wholly of inorganic substances is 3810.90.20.00 at a general (MFN) rate of Free. A flux containing 5% or more by weight of aromatic or modified aromatic substances is 3810.90.10.00 at a general (MFN) rate of 6.5%.
What is the duty on solder paste?
Soldering powders and pastes consisting of metal and other materials are classified in 3810.10.00.00, which carries a general (MFN) rate of 5%.
How do I classify a coating for welding electrodes?
Preparations of a kind used as cores or coatings for welding electrodes are classified in heading 3810. If the preparation consists wholly of inorganic substances it goes in 3810.90.20.00 at a general (MFN) rate of Free; other such preparations go in 3810.90.50.00 at a general (MFN) rate of 5%.
Source: USITC Harmonized Tariff Schedule, retrieved October 21, 2026.