HS code · 6-digit subheading
HS Code 8504.21 – Electrical transformers; liquid dielectric, having a power handling capacity not exceeding 650kVA
HS code 8504.21 is the 6-digit subheading for electrical transformers, liquid dielectric, having a power handling capacity not exceeding 650kVA. It is used for pole-mounted distribution transformers, pad-mounted transformers, small substation transformers, industrial oil-filled transformers and single-phase liquid dielectric transformers.
What HS 8504.21 covers
This category covers smaller liquid dielectric electrical transformers, which are essential for stepping up or stepping down voltage in various electrical systems. These transformers use oil or other liquid as an insulating and cooling medium, making them robust and reliable for outdoor and industrial applications. With a power handling capacity up to 650kVA, they are commonly found in distribution networks, commercial buildings, and light industrial settings. International trade in these transformers is driven by infrastructure development, urbanization, and industrial expansion globally. Key importers include developing nations investing in their power grids, as well as industrialized countries upgrading existing infrastructure, such as India, Brazil, and parts of Africa, alongside the USA and Germany. Exporters are typically countries with strong heavy electrical equipment manufacturing bases, like China, India, and European nations. Buyers prioritize efficiency, durability, and compliance with local electrical standards.
- Covers
- Pole-mounted distribution transformers
- Pad-mounted transformers
- Small substation transformers
- Industrial oil-filled transformers
- Single-phase liquid dielectric transformers
- Three-phase liquid dielectric transformers
- Network transformers
- Examples
- ABB distribution transformers
- Siemens liquid-filled transformers
- GE Prolec distribution transformers
- Eaton Cooper Power Systems transformers
- Schneider Electric oil-immersed transformers
Codes often confused with 8504.21
Common mistake. These can be confused with dry-type transformers (8504.3x) which use air or solid insulation, or larger liquid dielectric transformers (8504.22, 8504.23) if the kVA capacity is not carefully checked. The "liquid dielectric" and "not exceeding 650kVA" are the key differentiators.
Top exporters and importers of HS code 850421, 2025
In 2025, the largest exporter of HS code 850421 in UN Comtrade data was China, with 16% of world exports; the largest importer in UN Comtrade data was the United States, with 36% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Top exporters 2025 · share of world exports
- 1 China $570M 16% of world exports
- 2 Mexico $466M 13% of world exports
- 3 South Korea $349M 9.6% of world exports
World total: $3.6B Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $1.4B 36% of world imports
- 2 Germany $281M 7.2% of world imports
- 3 France $150M 3.8% of world imports
World total: $3.9B Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for 8504.21
Brazil does not split HS 8504.21: its NCM code is 8504.21.00.
All Brazil NCM codes in heading 85.04 →
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text is official; the English is our translation.
Questions about HS 8504.21
What is HS code 850421?
HS code 850421 is a 6-digit subheading in the Harmonized System that covers: Electrical transformers; liquid dielectric, having a power handling capacity not exceeding 650kVA. This category covers smaller liquid dielectric electrical transformers, which are essential for stepping up or stepping down voltage in various electrical systems. These transformers use oil or other liquid as an insulating and cooling medium, making them robust and reliable for outdoor and industrial applications. With a power handling capacity up to 650kVA, they are commonly found in distribution networks, commercial buildings, and light industrial settings. International trade in these transformers is driven by infrastructure development, urbanization, and industrial expansion globally. Key importers include developing nations investing in their power grids, as well as industrialized countries upgrading existing infrastructure, such as India, Brazil, and parts of Africa, alongside the USA and Germany. Exporters are typically countries with strong heavy electrical equipment manufacturing bases, like China, India, and European nations. Buyers prioritize efficiency, durability, and compliance with local electrical standards.
What products fall under HS code 850421?
Pole-mounted distribution transformers, Pad-mounted transformers, Small substation transformers, Industrial oil-filled transformers, Single-phase liquid dielectric transformers, Three-phase liquid dielectric transformers, Network transformers
What are common misclassifications for HS code 850421?
These can be confused with dry-type transformers (8504.3x) which use air or solid insulation, or larger liquid dielectric transformers (8504.22, 8504.23) if the kVA capacity is not carefully checked. The "liquid dielectric" and "not exceeding 650kVA" are the key differentiators.
Which countries are the top exporters of goods under HS code 850421?
In 2025, the top exporters of HS code 850421 in UN Comtrade data were China ($570M, 16% of world exports), Mexico ($466M) and South Korea ($349M). World exports came to about $3.6B, 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.
Which countries are the top importers of goods under HS code 850421?
In 2025, the top importers of HS code 850421 in UN Comtrade data were the United States ($1.4B, 36% of world imports), Germany ($281M) and France ($150M). World imports came to about $3.9B, 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.
How is HS code 850421 structured?
HS code 850421 is a 6-digit subheading under the Harmonized System. The first 2 digits (85) identify the chapter, digits 3-4 (04) identify the heading, and digits 5-6 (21) specify the subheading. This code is standardized globally by the World Customs Organization.
What is the Brazil NCM code for HS code 850421?
In Brazil, HS code 850421 is NCM 8504.21.00. The last two digits are 00 because Brazil does not split this HS code further.