HS Code 38.10 – Metal-pickling preparations; fluxes etc for soldering, brazing; welding powders, pastes of metal and other materials; preparations used as cores or coatings for welding electrodes or rods

HS code 3810 is a 4-digit heading in the Harmonized System that covers: Metal-pickling preparations; fluxes etc for soldering, brazing; welding powders, pastes of metal and other materials; preparations used as cores or coatings for welding electrodes or rods. Heading 3810 covers a range of essential chemical preparations used in metalworking and fabrication, crucial for industries from automotive to construction. It specifically includes metal-pickling preparations, designed to remove rust, scale, and other impurities from metal surfaces before further processing like plating or painting. Also classified here are fluxes and other auxiliary preparations for soldering, brazing, or welding, which facilitate the joining of metals by preventing oxidation and improving material flow. This encompasses welding powders, pastes, and preparations used as cores or coatings for welding electrodes or rods, ensuring consistent and strong welds. The scope is confined to *preparations* that serve these specific functions, not the raw chemical ingredients (which fall under Chapters 28 or 29) nor the finished metal articles or welding equipment (which are classified elsewhere, e.g., Section XV or Chapter 85). For customs brokers and trade compliance professionals, accurate classification under 3810 is vital for correct duty assessment, adherence to safety regulations, and ensuring smooth cross-border movement of these industrial consumables. This heading is fundamental to global manufacturing supply chains, enabling the production and repair of metal goods worldwide. As part of Chapter 38, it highlights the specialized nature of these chemical products tailored for specific industrial processes.

Metal descaling preparations, rust removal solutions, phosphoric acid-based pickling agents, soldering pastes, brazing fluxes for copper, aluminum soldering fluxes, welding electrode coatings, flux-cored welding wires (as preparations), submerged arc welding fluxes, anti-spatter preparations for welding, tinning fluxes, lead-free soldering fluxes, stainless steel pickling paste, etching solutions for metals, pre-fluxes for electronics, silver brazing fluxes, powder for gas welding, chemical cleaning agents for metal, flux for induction brazing, paste for soft soldering, preparations for surface activation of metals, flux for resistance welding, preparations for hot-dip galvanizing, electroplating pre-treatment chemicals.

A common error when classifying under HS 3810 is mistaking pure chemical compounds for these specialized preparations. For example, a single acid used for pickling might be incorrectly placed here instead of Chapter 28 (Inorganic chemicals) or 29 (Organic chemicals). Another mistake is classifying complete welding electrodes or rods under 3810; while their coatings or cores fall here, the finished electrodes themselves are typically found in Section XV (Base metals and articles of base metal) or Chapter 83 (Miscellaneous articles of base metal). Traders must ensure that the product is a *preparation* or *mixture* specifically formulated for pickling, soldering, brazing, or welding, rather than a raw material or a finished article, to avoid customs discrepancies.

In 2025, the top exporters of HS code 3810 in UN Comtrade data were Japan ($374M, 15% of world exports), the United States ($305M) and China ($257M). World exports came to about $2.4B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

In 2025, the top importers of HS code 3810 in UN Comtrade data were China ($293M, 11% of world imports), the Philippines ($286M) and Vietnam (about $201M). World imports came to about $2.8B, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.

HS code 3810 is a 4-digit heading under Chapter 38 of the Harmonized System. The first 2 digits (38) identify the chapter, and digits 3-4 (10) specify the heading. This code contains multiple 6-digit subheadings for precise product classification.