Product classification
HS code for Wirewound rheostats: 8533.31
Electrical resistors, wirewound variable, including rheostats and potentiometers, for a power handling capacity not exceeding 20W (excluding heating).
Classification of wirewound rheostats under HS 8533.31
Wirewound rheostats with a power handling capacity not exceeding 20W are classified under HS code 8533.31. This classification is governed by the physical construction of the resistor and its specific power rating. Wirewound resistors are manufactured by winding a resistive wire, typically an alloy like nichrome, around a non-conductive ceramic or plastic core. As variable resistors, rheostats allow the user to adjust the amount of resistance in a circuit, thereby controlling the current flow. The 20W threshold is a critical distinction in the Harmonized System, separating low-power components used in precision electronics from heavy-duty industrial versions. Under the Section XVI notes, electrical resistors (including potentiometers) are specifically assigned to heading 8533. The subheadings further refine the classification based on whether the resistor is fixed or variable, the material used (wirewound vs. other), and the wattage. For 8533.31, the device must be both wirewound and variable with a low power rating.
- Covers
- Low-power wirewound potentiometers for audio equipment
- Precision rheostats used in laboratory testing instruments
- Variable wirewound resistors for small motor speed control
- Adjustable dimmers for low-wattage lighting systems
- Calibration rheostats for electronic measurement devices
- Also under 8533.31
- Bourns 3362 series trimpots
- ALPS RK27 series audio pots
- Vishay Spectrol 132 series
- Panasonic EVU series
Codes often confused with 8533.31
Common mistake. The most common misclassification occurs with HS code 8533.39, which is designated for wirewound variable resistors with a power capacity exceeding 20W. Importers often fail to check the technical specifications for wattage, leading to incorrect filings. Additionally, these are sometimes confused with HS code 8533.40, which covers other variable resistors such as carbon-composition or cermet types. It is vital to confirm the resistive element is indeed wirewound to justify 8533.31.
Top exporters and importers of HS 853331 (the code used for wirewound rheostats), 2025
In 2025, the largest exporter of HS 853331 (the code used for wirewound rheostats) in UN Comtrade data was the United States, with 24% of world exports; the largest importer in UN Comtrade data was the United States, with 13% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 853331, not only wirewound rheostats.
Top exporters 2025 · share of world exports
- 1 United States $22M 24% of world exports
- 2 Germany $13M 14% of world exports
- 3 Mexico $13M 13% of world exports
World total: $94M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 United States $14M 13% of world imports
- 2 China $12M 11% of world imports
- 3 Germany $9.4M 8.6% of world imports
World total: $109M 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 codes for wirewound rheostats
Brazil splits HS 8533.31 into 2 NCM codes. Pick the one that matches your product:
- 8533.31.10Wirewound potentiometers, up to 20 W
- 8533.31.90Other wirewound variable resistors, up to 20 W
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about wirewound rheostats
What is the HS code for Wirewound rheostats?
The HS code for Wirewound rheostats is 853331 (Electrical resistors; wirewound variable, including rheostats and potentiometers, for a power handling capacity not exceeding 20W (excluding heating)). The HS code for wirewound rheostats with a power handling capacity of 20W or less is 8533.31.
How do I classify Wirewound rheostats for customs?
Wirewound rheostats is classified under HS code 853331 — Electrical resistors; wirewound variable, including rheostats and potentiometers, for a power handling capacity not exceeding 20W (excluding heating). This is a 6-digit subheading level code.
One more relevant question
Can a fixed wirewound resistor use this code? No, fixed wirewound resistors are classified under 8533.21 (less than 20W) or 8533.29 (more than 20W).
Which countries are the top exporters of wirewound rheostats (HS 853331)?
In 2025, the top exporters of HS 853331 (the code used for wirewound rheostats) in UN Comtrade data were the United States ($22M, 24% of world exports), Germany ($13M) and Mexico ($13M). World exports came to about $94M, 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 wirewound rheostats (HS 853331)?
In 2025, the top importers of HS 853331 (the code used for wirewound rheostats) in UN Comtrade data were the United States ($14M, 13% of world imports), China ($12M) and Germany ($9.4M). World imports came to about $109M, 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.
Is the HS code for Wirewound rheostats the same in all countries?
The base HS code 853331 for Wirewound rheostats is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for wirewound rheostats in Brazil?
Brazil splits HS 853331 into 2 NCM codes, so the right one for wirewound rheostats depends on the product's details: 8533.31.10 (Wirewound potentiometers, up to 20 W), 8533.31.90 (Other wirewound variable resistors, up to 20 W).