Product classification
HS code for Mill balls: 7325.91
Iron, grinding balls and similar articles for mills, other than of non-malleable cast iron.
Classification of mill balls under HS 7325.91
Mill balls are classified under HS code 7325.91, which specifically addresses grinding balls and similar articles for mills. This classification is determined by the material composition—iron or steel—and the manufacturing process, which is casting. According to the General Rules of Interpretation (GRI), products are classified based on their heading and any relative section or chapter notes. Since these items are cast articles of iron or steel intended for use in grinding mills, they fall under heading 7325. The subheading 7325.91 is reserved for grinding balls and similar articles, excluding those made of non-malleable cast iron, which would be classified elsewhere. The durability and specific spherical shape designed for industrial grinding processes define their placement here. The classification remains consistent regardless of whether the balls are used in the mining, cement, or chemical industries, provided they meet the metallurgical definition of cast steel or malleable iron. If the balls were forged rather than cast, the classification would shift to a different heading entirely, making the production method the primary determinant for this specific code.
- Covers
- Cast steel grinding balls
- Malleable iron grinding media
- Chrome alloy cast balls for ball mills
- Spherical cast iron media for pulverizing
- Also under 7325.91
- Magotteaux (grinding media)
- Moly-Cop (grinding balls)
- Scaw Metals (grinding media)
- Estanda (mill components)
- Metso Outotec (grinding solutions)
Codes often confused with 7325.91
Common mistake. A frequent error involves confusing 7325.91 with HS code 7326.11. While both codes cover grinding balls, 7326.11 is strictly for forged or stamped articles that have not been further worked. Another common mistake is attempting to classify these as machinery parts under 8474.90. However, because mill balls are considered consumable grinding media and are specifically named in Chapter 73, the specific article code takes precedence over the general machinery part code.
Top exporters and importers of HS 732591 (the code used for mill balls), 2025
In 2025, the largest exporter of HS 732591 (the code used for mill balls) in UN Comtrade data was China, with 40% of world exports; the largest importer in UN Comtrade data was Australia, with 16% 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 732591, not only mill balls.
Top exporters 2025 · share of world exports
- 1 China $287M 40% of world exports
- 2 India $183M 26% of world exports
- 3 Thailand $149M 21% of world exports
World total: $709M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Australia $121M 16% of world imports
- 2 Brazil $74M 9.6% of world imports
- 3 Ghana $45M 5.8% of world imports
World total: $769M 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 mill balls
Brazil classifies mill balls under NCM 7325.91.00: HS 7325.91 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about mill balls
What is the HS code for Mill balls?
The HS code for Mill balls is 732591 (Iron; grinding balls and similar articles for mills, other than of non-malleable cast iron). The primary HS code for cast iron or steel mill balls is 7325.91.
How do I classify Mill balls for customs?
Mill balls is classified under HS code 732591 — Iron; grinding balls and similar articles for mills, other than of non-malleable cast iron. This is a 6-digit subheading level code.
Are forged steel balls classified under 7325.91?
No, forged steel balls are classified under HS code 7326.11, as 7325.91 is reserved exclusively for cast articles.
Which countries are the top exporters of mill balls (HS 732591)?
In 2025, the top exporters of HS 732591 (the code used for mill balls) in UN Comtrade data were China ($287M, 40% of world exports), India ($183M) and Thailand ($149M). World exports came to about $709M, 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 mill balls (HS 732591)?
In 2025, the top importers of HS 732591 (the code used for mill balls) in UN Comtrade data were Australia ($121M, 16% of world imports), Brazil ($74M) and Ghana ($45M). World imports came to about $769M, 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 Mill balls the same in all countries?
The base HS code 732591 for Mill balls 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 mill balls in Brazil?
In Brazil, mill balls (HS 732591) is classified under NCM 7325.91.00.