Product classification
HS code for Spring washers: 7318.21
Iron or steel, non-threaded spring washers and other lock washers.
Classification of spring washers under HS 7318.21
Spring washers are classified under HS code 7318.21. This code is situated within Chapter 73, which covers articles of iron or steel. Heading 7318 specifically includes screws, bolts, nuts, coach screws, screw hooks, rivets, cotters, cotter-pins, and washers. Within this heading, the system differentiates between threaded and non-threaded articles. Spring washers are non-threaded fasteners designed to prevent loosening due to vibration or to maintain tension in a joint. The subcategory 7318.21 is dedicated specifically to spring washers and other lock washers. The classification is determined by the functional design of the washer—specifically its ability to exert a spring force—and its material composition of iron or steel.
- Covers
- Split ring lock washers
- Helical spring washers
- Belleville washers (conical spring washers)
- Wave spring washers
- Curved spring washers
- Toothed lock washers
- Also under 7318.21
- Nord-Lock washers
- Schnorr disc springs
- Fastenal lock washers
- Würth spring washers
Codes often confused with 7318.21
Common mistake. Spring washers are often confused with general non-threaded washers classified under HS code 7318.22. The distinction lies in the locking or tensioning function; if the washer is flat and lacks a spring-action design, it belongs in 7318.22. Another misclassification occurs with HS code 7320, which covers general springs. While spring washers exhibit spring-like properties, they are legally classified as fasteners under 7318 because their primary purpose is to secure components in a bolted or screwed joint.
Top exporters and importers of HS 731821 (the code used for spring washers), 2025
In 2025, the largest exporter of HS 731821 (the code used for spring washers) in UN Comtrade data was Germany, with 29% of world exports; the largest importer in UN Comtrade data was Germany, with 11% 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 731821, not only spring washers.
Top exporters 2025 · share of world exports
- 1 Germany $263M 29% of world exports
- 2 United States $100M 11% of world exports
- 3 China $85M 9.3% of world exports
World total: $921M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Germany $115M 11% of world imports
- 2 United States $83M 8.3% of world imports
- 3 Mexico $80M 7.9% of world imports
World total: $1.0B 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 spring washers
Brazil classifies spring washers under NCM 7318.21.00: HS 7318.21 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
EU Regulatory Requirements
This product falls under the Carbon Border Adjustment Mechanism (CBAM). Importers to the EU must declare embedded carbon emissions and purchase CBAM certificates.
Questions about spring washers
What is the HS code for Spring washers?
The HS code for Spring washers is 731821 (Iron or steel; non-threaded spring washers and other lock washers). The HS code for spring washers made of iron or steel is 7318.21.
How do I classify Spring washers for customs?
Spring washers is classified under HS code 731821 — Iron or steel; non-threaded spring washers and other lock washers. This is a 6-digit subheading level code.
Are stainless steel spring washers classified differently?
No, they are still classified under 7318.21 as they are articles of steel, though specific national tariff lines may distinguish between alloy and non-alloy steel.
Which countries are the top exporters of spring washers (HS 731821)?
In 2025, the top exporters of HS 731821 (the code used for spring washers) in UN Comtrade data were Germany ($263M, 29% of world exports), the United States ($100M) and China ($85M). World exports came to about $921M, 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 spring washers (HS 731821)?
In 2025, the top importers of HS 731821 (the code used for spring washers) in UN Comtrade data were Germany ($115M, 11% of world imports), the United States ($83M) and Mexico ($80M). World imports came to about $1.0B, 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 Spring washers the same in all countries?
The base HS code 731821 for Spring washers 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 spring washers in Brazil?
In Brazil, spring washers (HS 731821) is classified under NCM 7318.21.00.